The Enterprise — Mike Nardacci

Rocks in one of the many stone walls in the Helderbergs are easily forced out in winter frosts, creating gaps.

The Enterprise — Mike Nardacci

Potholes are ubiquitous during the seasonal changes from winter to spring, but this one is particularly deep.

The Enterprise — Mike Nardacci

The cliff behind the ice column that forms annually at Thacher Park is laced with fractures that expand and release rock fragments in winter and early spring.

The Enterprise — Mike Nardacci

A multi-ton boulder of hard metamorphic rock has been cleft in two by ice that formed and expanded in a fracture.

The Enterprise — Mike Nardacci

Due to frost wedging, great slabs of rock have spalled from this limestone outcrop south of the village of New Salem, forming a steep cliff.

The Enterprise — Mike Nardacci

Along the Beaver Dam Road, this exposure of the Esopus shale is gradually being reduced to gravel by frost action.

The Enterprise — Mike Nardacci

The impressive profile of Potash Mountain looming above Lake Luzerne formed when several small glaciers descending from its summit carved its pyramidal shape.

“Something there is that doesn’t love a wall,” Robert Frost wrote, “That sends the frozen ground swell under it,/And spills the upper boulders in the sun,/ And makes gaps even two can pass abreast.”

Of course — Robert Frost being Robert Frost — the astute reader soon realizes that the “something” to which he is alluding is a symbolic force beyond the natural one of a frost heave. “Frost is writing about something other than FROST,” a professor of mine once told our class, a statement fraught with multiple meanings. 

Nevertheless, this time of year the natural — and frequently destructive — effects of the past winter’s ice are in evidence just about anywhere one cares to look — perhaps most annoyingly in our pock-mocked city streets and country roads.

Appearing first as fine lines often resembling the strands in a spider’s web, fractures caused by the natural wear and tear of moving traffic begin to lengthen and interconnect, producing jagged pieces of gravel and leaving behind little indentations; these then also interconnect and become even larger pits which fill with water — and then the tire of your car hits what looked like a shallow puddle in the road followed by a sickening thud and the shuddering of both car and occupants.

And the culprit is frozen water — or, rather, the alternate freezing and thawing of water, phenomena that occur throughout the winter at our latitudes but become particularly frequent and destructive when winter begins to loosen its grip. 

The phase change of water from liquid to solid and back again wreaks destruction on any exposed porous surface and occurs repeatedly throughout the seasonal transition.

“Stay where you are until our backs are turned!” is what Robert Frost calls the “spell” to keep boulders in a stone wall in place, though the words themselves betray their futility. How often in February do we see work crews filling in potholes with steaming blacktop — only to have the fill ripped out and scattered forlornly over the road surface following the next snowfall or slush storm?

When torrential floods or massive snowstorms occur, we become all too aware of water’s destructive power in its various states, but because of its ubiquitous nature, we otherwise tend to take it for granted.  However, among many other ancient people, the Egyptians knew that their civilization depended upon the water in their great river — Egypt being “the gift of the Nile” — and they worshipped a god called Hapi as its spiritual embodiment; ancient Greeks built temples over springs, whose waters were considered not only essential for life but sacred.

Water is weird

But outside of a science classroom, we often tend to forget just what weird stuff water is. Reversing the behavior of other natural substances, water occupies greater volume as a solid than as a liquid, which is why a can of soda or a bottle of beer placed in a freezer will shatter when the liquid expands as it freezes;  likewise, unlike other substances, its density decreases when it becomes a solid.

And the phase changes of water involve amazing numbers of calories. Physics students know that, while it takes only one calorie of heat to raise one gram of liquid water by one degree Celsius, it takes 540 calories to vaporize that one gram when it reaches 100 degrees Celsius.

Take one calorie out of a gram and its temperature will drop by one degree — but if that gram of water is at zero Celsius, 80 calories must be removed to make it freeze. As it does, it will expand and become less dense, which is why ice floats.

And a good thing it does — for if ice were denser than water it would sink, causing many of our ponds and lakes to freeze solid in winter, wiping out all the life within them.

Most vitally, water is the absolutely essential ingredient for the existence of life as we know it, which is why the scientists known as “exo-biologists” are excited by the prospect of subsurface oceans on the moons known as Europa and Enceladus that orbit Jupiter and Saturn respectively.

Several years back, an early-season hiker on the Indian Ladder Trail at Thacher State Park was injured by a falling cobble-sized rock ripped from the cliff by winter’s ice, resulting in an extended closure of the trail. Apparently trying to conjure images of a dark conspiracy, an area daily newspaper subsequently published a story with a headline to the effect that the park maintenance staff “knew of” the danger beforehand. 

Of course they did — and so did every kid in New York State taking Earth Science! The implication that “something should have been done” is ludicrous. The mile-long trail follows the base of a cliff made of several different rock types, all of which are heavily fractured through natural weathering processes and all of which absorb water that freezes in winter, resulting in the shattering of rock known as “frost wedging.”

A photo taken in the Adirondacks shows a multi-ton boulder of the metamorphic rock known as schist that has been cleaved by this process. No amount of vigilance before the Indian Ladder Trail opened for the season could have accounted for every single crevice or fracture that was in danger of releasing a rock fragment.

The Helderberg escarpment has been eroding for millions of years, and the process will continue for millennia to come.  The broad talus slope that descends from the escarpment into the valley below is made up of billions of tons of rock weathered from it, ranging in size from giant boulders to sand grains — and these fragments do not fall without violent results.

The rocks of the Helderbegs generally fall into one of three types of sedimentary rock, formed hundreds of millions of years ago in the seas of the Devonian Period: limestone, shale, and sandstone.

Of the three, because of its density, limestone is generally the most resistant to weathering by frost wedging, though natural acids in rain and groundwater will cause it to dissolve. From a limestone outcrop south of the village of New Salem, great slabs of rock have been wedged by ice accumulating in the natural fractures in bedrock known as “joint partings,” forming a steep cliff .

Shale is petrified clay and can easily absorb water that can cause a solid rock exposure like one on the Beaver Dam Road above Thacher Park to be reduced to a pile of gravel by frost wedging. The talus slope below the the Helderberg escarpment is formed mostly from the on-site weathering of porous shale and sandstone bedrock, though it is littered with immense jagged boulders of the Manlius and Coeymans limestone layers that have broken away from the cliffs and gone crashing down from the plateau.

Ice Age changes

Much of New York State’s landscape was changed radically starting 1.5 million years ago with the onset of the Pleistocene Epoch, more commonly known as “the Ice Age,” though it was only the most recent of several that Earth has experienced over the billions of years of its existence.

In the Helderberg area, the steep faces and flat tops of Bennett Hill in Clarksville and Vroman’s Nose in Middleburgh show the effects of the movement of the continental ice sheet. Laden with rock fragments torn from bedrock by frost action, the glaciers acted like gigantic bulldozers sculpting and scraping the bedrock, often with spectacular results.

Pyramidal Potash Mountain that looms above Lake Luzerne got its unique shape when several small glaciers descending from its summit tore away its dense metamorphic bedrock.  Had the glaciers persisted for a few more thousands of years, Potash Mountain might have become a miniature version of Switzerland’s Matterhorn.

A graph of daily temperatures as the year in the Northeast progresses from January to June would show a constant variation from cold to warm and back to cold again. It must be remembered that an “average” temperature is simply the mean between two extremes, and it is not unusual in this part of the country to have a day in the 70s in February and a snowy day in May — though the general temperature trend obviously is upward.  

Warm days and below-freezing nights are said to be ideal for maple syruping. But they certainly can wreak hell on our roads and rocks.

Location:

— Photo by Mike Nardacci

Commemorating James and Guildford Otto who died in the Civil War, this severely weathered marble monument stands on a sunny hillside in the Town of Rose Cemetery and has always saddened the Nardacci family.

— Photo by Mike Nardacci

The impressive, near-pristine Briggs family monument, carved from gray granite still shows high polish after more than 100 years of exposure to weathering in the Town of Rose Cemetery.

— Photo by Mike Nardacci

Many marble headstones in Knox’s High Point Cemetery, with its elegant gateway, are still legible, due largely to the cemetery’s dry, sunny location.

— Photo by Mike Nardacci

Toppled stones gathered in a humid, shady portion of High Point Cemetery are heavily weathered, their inscriptions largely erased.

— Photo by Mike Nardacci

The Reidsville Cemetery with its wrought-iron gate seems the quintessential Helderberg burying ground.

— Photo by Mike Nardacci

The towering evergreens of the Reidsville Cemetery create a dark, humid environment conducive to many agents of weathering, destructive even to very hard rock such as granite.

Someone once described the goldenrod that seems ubiquitous this autumn as “quill pens signing summer’s eviction notice.”  Whether it was the blooming of goldenrod or some other harbinger of summer’s end that inspired the autumnal imagery of his classic, melancholy “Elegy Written in a Country Churchyard,” English poet Thomas Gray wandered through a rural cemetery “Far from the madding crowd’s ignoble strife” and in the evocative silence brooded over the lives of the souls interred there.

From their names and fleeting scraps of information carved on their tombstones, Gray inferred details of their triumphs and tragedies, their loves and losses, and their aspirations and failures, now marveling at the longevity of some or mourning the brevity of the lives of others. He read more into the moss-encrusted stones than most observers would — or would care to.

But it is a little-known fact that, to generations of geology professors, country cemeteries have frequently served as outdoor laboratories for the demonstration of many aspects of the cycles of weathering and erosion.

These are points that can, of course, be easily made using a textbook with its graphs and photographs.  But geology — perhaps more so than any of the other natural sciences except for biology — is best taught as a field science.

This is a fact that I can personally attest to from memorable courses I have taken at Acadia National Park, the Grand Canyon, Mammoth Cave, and other venues in which the complexities of the effects of mineral content, climate, exposure, and age on the weather-erosion cycle are clearly displayed.

And in a number of those courses, the professors packed students into vans and shuttled us off to old country cemeteries in which whatever geologic principle being taught was clearly and sometimes dramatically displayed.

The idea for this article came to me on a hot day in late August during a visit to the Town of Rose Cemetery in western New York in which some of my mother’s ancestors are buried. The cemetery sits on the slope of a drumlin, a glacially-deposited hill that is one of hundreds scattered across much of western New York and the Northeast. 

Drumlins and related glacially-formed hills called kames have frequently served as the locations of cemeteries, partially because their elevation above the surrounding landscape has symbolic meanings, but also because their composition of an unconsolidated mixture of soils and rocks makes them well-drained — ideal for burials.

One thinks of the high and windy hill that is the site of the Grover’s Corners cemetery in the melancholy third act of Thornton Wilder’s classic play “Our Town.”

Perhaps it is partly the inevitable association of cemeteries with Halloween that evokes their solemn atmosphere, and in this one even on a bright late-summer day there was a particular monument that has always saddened our family.

It stands a little over five feet tall and is carved from white Vermont marble, a very ancient rock formed during the Ordovician Period, some 450 million years ago, during the event known as the Taconian Orogeny.

The ancient ocean known as the Iapetus that lay off what is now the east coast of the United States was beginning to close as the process known as plate tectonics brought small land masses into collision with it, pushing up mountains and forming marble through metamorphism of pre-existing limestone.

Next to the monument, a bronze receptacle holds a flag, indicating that two of the dead memorialized here — my mother’s great uncles — died in the Civil War. The young men were inspired by the powerful words of  “The Battle Hymn of the Republic” — “As [Jesus] died to make men holy/Let us die to make men free.”

Their tombstone records that one of them named James Otto starved to death and was buried in Andersonville, the infamous Confederate prison in Georgia; the other, his brother Guilford, is actually interred here.  He and a fellow soldier were murdered by a Pennsylvania farmer with pro-slavery sympathies when they were sent to him purchase horses for the troops.

The memorial must have been splendid when it was erected around 1865. Today, the graven inscriptions recording the young men’s sacrifices have become difficult to read. In a decade or two, the inscription will be obliterated and it will stand as do so many other old marble headstones and monuments, their honored dead anonymous.

Marble is a very hard, dense rock that resists the absorption of water from rain or melting snow and therefore does not easily break down due to freezing and subsequent thawing in the process known as physical weathering; however, marble is composed of calcium carbonate, and as any high school chemistry student knows, calcium carbonate dissolves in acid.

Falling rain and fog pick up minute amounts of carbon dioxide from the atmosphere, producing a mild solution of carbonic acid. Ordinarily, carbonic acid of this strength is harmless to plants and animals but over many years it will slowly but relentlessly dissolve any calcium carbonate surface in a process known as chemical weathering.

Consequently, given that the monument was erected in Rose Cemetery over 150 years ago, it is surprising that the inscriptions are legible at all. But their saving grace has been the fact that the monument is situated on an open slope facing south, which means they are exposed to sunlight virtually all day when the sun is not obscured by clouds.

This results in the constant warming and drying of the surface, preventing its rapid dissolution and largely preventing growth of lichens and moss — the same factor that causes them to grow mainly on the north side of trees. They secrete small amounts of natural acids that in a damper, more sheltered environment can wreak havoc on organic or mineral surfaces — such as marble headstones.

Farther up the slope is another monument marking the graves of some other ancestors — in this case, my mother’s great-grandparents, whose surname was Briggs.

It was carved from gray granite, an igneous rock brought perhaps from New Hampshire or Maine and formed during the Devonian Period, in an event known as the Acadian Orogeny, some 380 million years ago; at that time, an ancient landmass known as Avalon — which would eventually become Europe — was subducting under North America and creating massive amounts of igneous rock through explosive volcanic action.

The monument stands over five feet tall and its rectangular base holds a massive sphere, an unusual design in this relatively modest graveyard. But although it, too, is over 100 years old, from its appearance one might think it had been placed there last week.

The sphere and the sides of the monument were highly polished and on a sunny day the reflection from the sphere can be blinding. Granite’s two major constituents are visible crystals of feldspar and quartz, both of which are capable of appearing in a spectrum of colors, though varying shades of pink and gray are most common.

The important fact is that neither of these minerals is easily susceptible to chemical weathering and given the extreme hardness and density of the stone and its openness to sunlight, even after a century the monument looks as fresh as if it had been erected very recently.

Almost all of the older headstones and monuments in the Rose Cemetery are carved from either marble or granite and their presence tells another story. Neither of these stones is found locally near the Rose Cemetery; they must have been imported from out of state and their inscriptions carved painstakingly by hand — which bespeaks the affluence of many of the cemetery’s silent residents and their families.

Contrast this one with many of the mossy pioneer cemeteries scattered throughout the Helderbergs in which many of the headstones of the hard-working people buried there were carved either from the native limestone or the local somewhat porous sandstone — both dating from the Devonian Period — and observe how the names of the deceased and their memorial inscriptions have largely vanished.

However, the High Point Cemetery above Altamont on Old West Road with its elegant entrance gate and meticulously-constructed stone wall is another example of a southerly-facing country graveyard in which both marble and limestone monuments a century or more old are still well-preserved.

Many of these stones are carved from marble but they face the southwest, and the view across Old West Road to a wide field is unobstructed by trees; consequently, the stones are dried and warmed from sunrise to sunset on days when the sky is not mostly overcast.

Many of the headstones are on a gentle slope and apparently were never set into concrete bases, and as a result they show the tilting common among monuments in older cemeteries caused by the slow, steady downward movement of the ground known as soil creep.

Frequently, in older cemeteries, this can cause the stones to topple, but High Point Cemetery is obviously lovingly maintained, its grass trimmed and even its very old headstones mostly upright. 

However, a collection of toppled, heavily-weathered markers in the shaded rear of the cemetery has been set aside against the old stone wall, their inscriptions mostly vanished along with record of the deceased they were intended to memorialize.

And, in a few cases, small, closely-spaced, rough-cut markers without inscriptions — harvested, perhaps, from tilled fields or pulled from stone walls — tell sad stories of deceased infants.

Shade can help to speed the forces of weathering and erosion in a humid, changeable climate such as ours — and a prime example is the venerable old cemetery near Reidsville.

With its ancient, very tall balsams and spruces, the cemetery is situated behind an evocative, slightly rusted cast-iron fence — the stereotypical locale for a Gothic ghost story. In the late 1800s and early 1900s, Reidsville was a village with a population of over a thousand.

Largely due to the quarrying activities that supplied the attractive sandstone known as Helderberg bluestone to many localities in the Albany area, the village grew, at one time boasting a hotel, a popular tavern, two churches, two retail stores, and a blacksmith shop — traces of which have largely disappeared.

The quality of the granite and marble stone monuments in the cemetery is once again evidence of the relative affluence of its occupants. Yet, although the majority of the headstones face east and could therefore be expected to get drying sunlight at least in the morning, the immense trees cast much of the cemetery into shadow and their thick boughs steadily drip moisture from rain and melting snow.

Some of the trees show the growth of the lichen commonly known as “Old Man’s Beard,” which resembles Spanish moss and flourishes in very humid boreal forests, especially those near great bodies of water such as the Acadian Coast of Maine and Canada. The damp, pitted ground surrounding many of the old headstones is deep with mosses, which do not flourish in sunlight.

As a result, even some once-stately granite monuments show evidence of heavy chemical weathering and are stained by dark lichens.  The contrast between them and some equally old, much-less-weathered stones in the more open rear sections of the cemetery is sharp.

And especially on a gloomy autumn day, the scene epitomizes Thomas Gray’s lines:

“Beneath those rugged elms, 

   that yew-tree’s shade

Where heaves the turf

   in many a mould’ring heap’

Each in his narrow cell

   forever laid,

The rude forefathers

   of the hamlet sleep.”

(In Gray’s time, the word “rude” had nothing to do with manners but rather denoted “unsophisticated.”)

In recent decades, upright stone grave markers have largely gone out of fashion due to the great expense of preparing them and in many newer areas of cemeteries they are prohibited, replaced by bronze markers which lie flat upon the ground.

An alloy of copper and other metals, bronze tends to resist chemical dissolution although after decades of exposure to moisture it may weather to a dull shade of green like a copper penny. But being at ground level, if not carefully maintained, these markers can soon be covered by grasses and weeds, hiding their inscriptions as surely as if they had been dissolved away.

A walk through a cemetery, especially one with familiar names on the memorials, may bespeak many aspects of the history of a town and its inhabitants along with many other profound thoughts that cemeteries are supposed to bring.

But a close examination of its location, the composition of its monuments and their condition reveals much about its geologic history as well: accounts of continental collisions, ancient rock changing through metamorphism, new rock forming from violent volcanic eruptions, and the much more recent passage of the great ice sheets. In all — a veritable textbook of geology.

Location:

— Photo by Mike Nardacci

Into the precipitous tufa cliffs of the Puye mesa, ancient people carved shallow caves as dwelling places with staircases and walkways to connect them.

— Photo by Mike Nardacci

Atop the mesa, free-standing buildings of Puye Pueblo have survived for centuries due to their durable construction and the dry climate. Thousand-year-old timbers support ceilings and upper floors and their shadows form intricate patterns on the ruined walls.

— Photo by Mike Nardacci

The ground at Puye is littered with obsidian fragments and with thousands of fragments of pottery from different time periods in the pueblo’s history.

— Photo by Mike Nardacci

The unearthly landscape around Acoma Pueblo is studded with mesas, buttes, and pinnacles eroded over millennia from thick layers of sandstone.

— Photo by Mike Nardacci

From a distance, the adobe dwellings of Acoma look like jagged boulders piled atop the mesa.

— Photo by Mike Nardacci

The beautiful church of St. Estaban is a masterpiece of adobe architecture.

— Photo by Mike Nardacci

In the Acoma visitors’ center are cases displaying the intricately-painted pottery for which the pueblo has long been famous.

— Photo by Mike Nardacci

Traditional dwellings in Acoma has upper levels accessed by ladders. The ones on the right are topped with struts carved to represent thunderbolts.

— Photo by Mike Nardacci

Reservoirs like this one supplied ancient residents with water from rain and snowmelt. Next to it is the only tree that grows on the mesa.

Northern New Mexico and the “Four Corners” area of the Southwest are dotted with ruins of the ancient pueblo people whose sudden evacuation of their traditional villages some 800 years ago constitutes a major mystery in the archeology of pre-Columbian America.

Modern pueblo people have oral traditions that connect their ancestors, often grouped under the term “Anasazi,” to many of these ruins. These ancients occupied thousands of settlements, extensive or miniscule, in the high desert, many remnants of which are surprisingly well-preserved in the intensely dry climate.

The majority are cliff dwellings but a great number are freestanding buildings sometimes of three or four stories, all constructed from the local bedrock. Many clues seem to point to the fact that they were abandoned with stunning suddenness.

To enter a dilapidated dwelling in one of the crumbling ruins with a guide or on an unaccompanied hike and find household goods such as smashed pottery, broken corn grinders, and even remnants of last meals is to be confronted with a situation suggesting very sudden abandonment coupled with actions intended to prevent any future occupants from making use of the contents.

The Anasazi did not have a written language and only the ruins and the thousands of enigmatic paintings and carvings on rock — known respectively as pictographs and petroglyphs — offer scientific clues to the sudden abandonment.

Timbers of ancient tree trunks incorporated into the ruins indicate that around 1200 A.D. the Southwest was hit by a devastating century-long drought that might have provoked widespread conflict among the pueblos.

Archeological digs in the last 50 years have begun to uncover evidence not only of terrifyingly brutal raids but of cannibalism as well. These discoveries are jarring compared to the politically-correct image of the ancestral people of the Southwest living peaceful, harmonious lives — but as the author of a National Geographic article on the Anasazi wrote some years ago, the ancient people did not live their lives for the approval of 21st-Century sensibilities.

And yet in some quarters — particularly among the Navajo people — the very word “Anasazi” has come to be politically charged. A term with Navajo origin, it is said that it can be translated as either “ancient ancestors” or “ancient enemy.”

The latter rendering offers support to the oral traditions among some pueblo people that the predecessors of the Navajo descending from their ancient home in Canada drove them from their homes and villages.

But the actual events are far in the past and archeological evidence is ambiguous. In any event, whatever the cause of the sudden and mysterious migration, the inhabitants of the prehistoric stone dwellings seem to have fled mainly to the south of their traditional homelands to become the ancestors of today’s pueblo people.

Puye Cliff Dwellings

One of the more impressive abandoned ancient sites lies an hour’s drive northwest of Santa Fe, New Mexico, and is known as the Puye Cliff Dwellings which the people of the modern Santa Clara Pueblo identify as their ancestral home.

Pronounced “POO-yay,” the ruins are situated on a lofty mesa just east of a gigantic volcanic crater known as the Valles Caldera that resulted from a devastating eruption around 1.2 million years ago. The eruption formed vast layered beds of soft rock known as pumice and tufa as well as the black volcanic glass obsidian, which have eroded into hills and mesas.

The softness of the pumice and tufa made it easy to carve shallow caves and stairways into the strata while the obsidian could be worked into knives, spear points, and arrowheads.

In addition, the base of the cliffs and the top of the mesa were deeply littered with shattered angular rocks that could be stacked into walls and mortared with mud to produce free-standing single- or two-story dwellings or used to line the partially-underground sacred spaces called kivas. Their geometric shapes and the shadows that fall on them in the harsh desert sunlight create a curiously contemporary look suggestive of cubist and minimalist art.

The top of the mesa is littered with fragments of pottery from different eras, many of them showing complex, colorful designs, as well as flakes of obsidian left from cleaving arrowheads and knives from larger chunks of the rock. Since these materials were used by their ancient forebears, modern pueblo people regard them as worthy of respect and visitors are urged not to remove them.

But contemporary pueblos have different explanations for why the fragments are there. Some claim that, since they came from the earth in the first place, the respectful thing is to allow them to return to the ground, while others will insist that the ancient inhabitants smashed their household items upon deserting their ancestral homes to prevent invaders from making use of them, just as many archeologists have argued.

Native American guides at Puye tell visitors that the ancient builders chose the location because its steep surrounding cliffs made it easily defensible, a site that would be abandoned only under great pressure — seeming to support the latter interpretation of the ubiquitous fragments.

Puye today is a barren place — parched, and exposed to the unforgiving New Mexican sun. As with many other ancient sites in the Southwest, the nearest water source is a small stream at some distance from the base of the mesa.

The thought of the women of Puye hauling water in jugs up steep steps and ladders to reach the top while the men trudged into the far green hills of the caldera in search of game rapidly destroys any romantic notion of the lives these people led, which from all archeological evidence was, as the cliché goes, “brutish and short.”

And yet, the stark elegance of the ruins and the intricate designs on the pottery fragments speak of a creative sensibility that even the harshness of daily life in Puye could not squelch.

Acoma Pueblo

An hour’s drive west of the city of Albuquerque on Route 40 is Acoma, another pueblo with an ancient history. Where the side road leading to it departs from Route 40, it first passes clusters of modern houses with air-conditioning units and satellite TV dishes — signs of the affluence brought to the contemporary Acoman people by the presence of a casino.

The road next traverses miles of evocative New Mexican scenery: steep, rolling, sandy hills fragrant with wild sage, dotted with junipers, pinyon pines, and the beautiful but poisonous datura; but it then passes into an almost unearthly world of jagged buttes, pinnacles, and mesas eroded from great strata of red and tan sandstone deriving their tints from oxides of iron.

Acoma Pueblo — known as “Sky City” — emerges slowly from the landscape, first appearing to be a scattering of enormous cubical and rectangular blocks of the sandstone scattered across the top of a mesa above precipitous cliffs. Closer, the blocks acquire tiny windows and what appear to be spindly ladders climbing to smaller blocks perched atop larger ones.

From the Acoma Visitor Center, a modern paved road ascends the mesa in a series of broad curves.  Unlike Puye and the thousands of other prehistoric sites scattered across the Southwest, Acoma Pueblo is still occupied.

The people of Acoma have a long history that begins — as with the stories of so many of the pueblos — in times cloaked in legend and mystery. East of the mesa on which Acoma sits is another rocky citadel known as “Haika” and, according to tribal legend, it is the ancestral home of the people of Acoma.  Regarded as sacred, Haika is off-limits to everyone, including — and perhaps especially — to archeologists and hikers.

At some point in the past, according to oral tradition, the Acomans left their legendary ancient home for reasons mysterious and moved to their present home in the sky on which they have dwelt for at least 1,000 years. There followed times of both peace and turmoil, climaxing in the revolt against their Spanish conquerors known as the Pueblo Rebellion.

Incensed by the Spaniards’ enslavement of their people and by forced conversion to Catholicism, the people of Acoma and other pueblos rose up and drove the Spaniards from their lands. And yet — paradoxically — the proud Acomans and the citizens of many modern-day pueblos are intensely religious, mixing fervent Catholicism with elements of their traditional religions in ways that — like Haika — are off-limits and mysterious to non-pueblo people often known collectively as “Anglos.”

The beautiful church dedicated to Saint Estaban (Saint Steven) is proudly displayed as the spiritual center of Acoma Pueblo. The church is constructed of the local sandstone and mortar, is fitted with wooden supports and railings carried from many miles away, and is covered in adobe formed from mud mixed with wild grasses; hence, it echoes the Biblical “bricks with straw” of the captive Hebrews in Egypt.

Acoma has been famous for centuries for its intricately-decorated, thin-walled pottery that is still sold by individual craftspeople and in the galleries of Santa Fe. The pottery is molded from a deposit of clay reputed to be over five miles from Acoma, and, like the artisans of all of the pueblos, these artisans keep the sources of the clays carefully guarded secrets.

A large sampling of traditional Acoman pieces is displayed in a museum in the pueblo’s visitors’ center. From there, guided tours ascend the mesa, with travelers riding in air-conditioned vans that seem to move through time as well as space, for atop the mesa the traditional dwellings have changed little over a thousand years and give a clear idea of what the great citadels of Mesa Verde, Chaco Canyon, and Canyon de Chelly must have looked like before their sudden abandonment.

The adobe dwellings climb to two or three stories, accessed by sturdy ladders joined at their tops by beams carved to evoke thunderbolts symbolically.

Some of the individual houses of “Sky City” are hundreds of years old, and none have electricity, central heating, air-conditioning, or indoor plumbing. Several shallow reservoirs carved into the largely impermeable sandstone were used by the ancient occupants to hold rainwater and snowmelt.

However, concessions to basic necessities have been made: vans transport water for drinking, cooking, and washing to the inhabitants, space heaters and wood stoves provide heat for cooking and warmth, and a series of porta-potties are maintained by the pueblo.

The thick adobe-covered walls of the residences hold in heat in winter and keep the interiors relatively cool in the sometimes fierce summer heat — and then, the high elevation of the pueblo frequently provides a cooling breeze. But in other ways those Acomans who have not left the mesa for modern comforts — numbering today only about 15 — are indeed living the ways of their ancient predecessors. 

On the other hand, on the occasion of major religious feasts and tribal celebrations, hundreds of Acoman people return to their ancestral homes on the mesa and also live for a time as their ancestors lived and keep alive tribal traditions.

Unlike the guides at Puye who readily assert that the mesa top was selected for purposes of defense, docents at Acoma explain that their high mesa was chosen because it brought the inhabitants above the rugged surroundings and closer to the sky and to the stars that were such a source of wonder and mystery to the ancient people.

Perhaps both explanations are correct. The view from “Sky City” reveals an ancient landscape sculpted from thick strata of colorful sandstone eroded into bewitching shapes by the agents of water, wind, and ice, the subject of many tribal stories that are closely guarded from “Anglos.”

But the proud people of Acoma are happy to share much of their heritage with the outside world during times of major feasts and celebrations.

Acoma on Christmas Eve is legendary throughout central and northern New Mexico. Hundreds of the pueblo people gather on the mesa for midnight Mass at St. Estaban and for visits with friends and family — and the night echoes with ancient songs.

Then the road ascending to the top of the mesa and the roofs of family dwellings are lit with many thousands of “farolitos,” the iconic Southwestern Christmas decorations made from small paper bags lit by candles within, and the twinkling lights of the farolitos mingle with the stars in the clear New Mexican night.

And then, even Anglos understand why Acoma is called “Sky City.”

Location:

— Photo by Mike Nardacci

The Onesquethaw Creek south of Clarksville emerges from the woods and flows for a time along Lower Flat Rock Road, exposing its strange topographic features to easy viewing.

— Photo by Mike Nardacci

Erosion and chemical solution have formed a series of descending terraces, some partially blocked by vegetation. Water flows over, through, and around these terraces to create a confusing maze.

— Photo by Mike Nardacci

Becraft Limestone contains massive quantities of fossilized fragments of ancient shellfish called brachiopods, visible as crescents or rings. A pair of sunglasses is included for scale.

— Photo by Mike Nardacci

Close-up of a section of the streambed showing the confusing maze and some temporarily isolated potholes providing mini-environments for minnows, pollywogs, and water bugs.

— Photo by Mike Nardacci

The Onesquethaw continues its southward flow through channels and potholes in the Becraft Limestone, eventually to join up with the Coeymans Creek before entering the Hudson River.

The stream called “Onesquethaw” undergoes extensive changes as it flows from its placid source in our portion of the Appalachian Plateau known locally as “the Helderbergs.” It incises its way through several rock layers — or “strata” — from the Devonian Period, which are between 360 and 400 million years old.

It has formed canyons, flows lazily over stretches of level terrain, and gurgles over gentle rapids and through potholes. Eventually it joins with Coeymans Creek before discharging into the Hudson River where its waters mix with those of thousands of other tributaries on the river’s course toward the Atlantic Ocean.

Some of the Onesquethaw’s most rugged and picturesque segments are off limits to most hikers as it flows through private lands; however, a stretch that parallels Lower Flat Rock Road off the section of Route 443 known as the Delaware Turnpike is easily accessible by car or bike and provides a quiet place to reflect on our area’s almost unimaginably long geologic history and the thoughts that changing seasons bring.

Privately-owned Helderberg Lake lies just north of Route 443 where it briefly runs congruent with Route 85. The lake was enlarged by an artificial dam in the 1930s and at its southern end its overflow becomes the Onesquethaw Creek as it cascades down a series of terraces and has carved out a steep gorge that descends for a mile or so as it plunges out of the steep hills of the town of Berne.

Almost entirely on parcels of private property, the gorge is formed from the thin-bedded Hamilton rock layers, strata composed of dark sandstones and shales. About 220 million years ago, a vast landmass that was to become Europe was beginning collision with proto-North America in one of the great movements known as plate tectonics.

The collision was closing the body of water that had divided the two landmasses and was pushing up a towering range of mountains in what is today eastern New England. Rain and snowmelt washed millions of tons of sediments from the slopes of these ancient mountains, filling in the waterway between the land masses and forming a series of interlocking deposits termed by geologists “the Catskill Delta.”

The deposits eventually turned to rock and are visible in western Albany County and throughout the extensive eroded plateau known as the Catskill Mountains.

This material alternates between being moderately resistant to stream erosion and poorly resistant, and thus the gorge below Helderberg Lake frequently exhibits a profile similar to that seen in many canyons in the West such as the Grand Canyon: a series of alternating steep and gradual slopes covered with piles of enormous quantities of eroded fragments called “talus.”

Near the area where Wolf Hill Road, Route 85, and Route 443 intersect, the Onesquethaw has cut down through the sandstone and shale layers to the Onondaga Limestone, the highest stratum of limestone in Albany County. The Onondaga is a hard, clean gray stone, indicative of its formation during the Devonian Period in clear, shallow, warm waters.

It is rich with fossils of many kinds of corals and in places features nodules and beds of chert, a dense rock commonly known as flint composed of silica. A number of extensive Albany County caves have formed in this layer.

For the next couple of miles, the stream runs parallel to Route 443 over nearly flat terrain with a surface bedrock of the Onondaga which in this stretch is highly fractured. In dry times of the year, the stream may flow entirely under the exposed streambed leaving it bleached and dry. In periods of heavy storms and snowmelt, the Onesquethaw boils to the surface and, gathering temporary energy from the flood pulse, may create whirlpools and rapids as it flows south toward Clarksville.

But approaching the hamlet, the stream’s path is temporarily diverted east by imposing Bennett Hill, a glacially-sculpted “rock drumlin” composed of the Hamilton strata. Eroded by the mile-high glacier that passed over it thousands of years ago, the step-like terraces of Bennett Hill are visible for many miles.

The Onesquethaw again becomes somewhat energized as it cuts through the limestone at the base of Bennett Hill and flows down through another impressive canyon. Here the stream encounters an extensive series of faults whose “slickensides” — tell-tale parallel grooves carved into the bedrock during an earthquake — are visible in sections of the canyon walls and the streambed, and in places the strata are bent and contorted by the movement of the ancient fault.

Within the canyon are small caves and springs, plunge pools, enormous potholes, giant boulders and slabs detached from the bedrock, and thick deposits of sediments composed of many rock types, some carried down from the Helderbergs, others left behind long ago by the retreating glaciers.

But in this stretch, the Onesquethaw is described as an “underfit” stream, meaning that with its average velocity — which for most of the year in these modern times is not much more than a trickle — it is incapable of eroding great chunks of the canyon’s hard bedrock or transporting and polishing large boulders. Much of this erosion occurred at the end of the glacial period when the Onesquethaw may have carried hundreds of times its present-day volume due to the melting of the glaciers.

As the Onesquethaw approaches the eastern boundary of the village, it cuts down into the crumbly Esopus Shale and for a stretch of several hundred feet it has exposed the marvelous fossils characteristic of the Esopus known commonly as “rooster tails.” These fossils represent a vast colony of tube worms whose feeding tunnels radiate out from a single point.

They indicate an ancient environment of relatively deep, calm water in which the delicate worms could have remained anchored to a single point on the sea bottom for a lifetime and burrowed through the murky organics-laden mud absorbing nutrients.

Just beyond the rustic stone bridge over the Onesquethaw on Tarrytown Road there is a pull-off on the left side of the road where a short path leads to the stream’s edge and offers a dramatic view of strata contorted by the movement of an ancient fault.

Beyond this point, the Onesquethaw is not visible from any public road and flows through private land. It continues to cut downward through the Esopus Shale and cascades over an impressive waterfall into a plunge pool.

It finally incises its way through the entire exposure of the Esopus and comes into contact with an even older Devonian layer known as the Becraft Limestone. But it is not until the stream bends and enters the wide, shallow valley through which passes Lower Flat Rock that it again becomes easily accessible and enters one of its most evocative sections.

Here for a thousand feet or so paralleling the road the Onesquethaw flows due south and is bordered on both sides by a forest of hemlocks and pines, floored by ferns, mosses, and other vegetation that flourishes in humid, shady environments. The stream itself broadens out and descends a series of low terraces producing miniature rapids as it continues through a bewildering maze of gurgling and babbling channels, potholes, and plunge pools.

The Becraft limestone layer has a thickness of only about 20 feet in this part of the county, but along Lower Flat Rock Road the rock has been smoothed off by the passage of the ancient glaciers in a broad plain known to geologists as a “bench.” Although much of the bedrock is covered here by a thin layer of soil and the forest it supports, the Onesquethaw’s path reveals the Becraft with its fascinating collection of fossils and erosional features.

The Becraft is a very hard rock and, because its surface was subjected first to abrasion by the glaciers and subsequently polished naturally over centuries by tiny water-borne sediments acting like fine sandpaper, exposures show the clean, gray limestone is flecked with thousands of closely-packed fossils. Mainly these are the shells of sea creatures known as brachiopods and they stand out as shiny white circles or crescents.

The Becraft resembles a rock type called “coquina,” which consists of great masses of fragments of sea shells naturally cemented together by calcium carbonate and often found near reefs and on the coast of Florida and islands in the Caribbean Sea. That most of the shells have been shattered indicates that the rock formed millions of years ago in relatively shallow-water environments in which the shells were subjected to violent agitation and deposition by waves in Devonian seas.

In addition, the Becraft in the streambed shows many fractures and joints — cracks caused by repeated freezing and thawing over centuries as well as expansion of the bedrock as upper layers are removed by erosion.

Because the limestone and its fossils are made of calcium carbonate, the rock is subject to chemical weathering by mild natural solvents such as carbonic acid, formed when water absorbs carbon dioxide as it falls through the atmosphere or flows over rotting duff on the forest floor.

As a result, the mildly acidic Onesquethaw waters have worked their way through every crack and crevice in the streambed, dissolving the maze of channels and potholes visible along Lower Flat Rock Road. Small channels encounter larger ones, fractures lead into potholes and plunge pools, and the tiny distributaries enter a confusing pattern of flow, sometimes briefly backwards or sideways or in miniature whirlpools, but eventually forward toward the Hudson under the pull of gravity.

Tiny dams formed by the presence of water-loving plants or water-borne debris create miniature pools of slow-moving or still water in which minnows and pollywogs and water bugs find refuge, feeding on tiny prey or bits of organic matter carried by the stream.

And of course, the patterns of flow and the sounds they produce change with the seasons and the weather.   Snowmelt and seasonal rainstorms raise the volume of the stream, causing the channels to overflow and create earnest-sounding if temporary rapids.

In dry times — especially late summer and fall — low flow in the Onesquethaw reduces the sounds of the stream to whispers. In winter, thick layers of ice form on the bedrock beneath the overhanging boughs of hemlock, creating weirdly-sculpted shapes in the streambed as well as yet more channels and dams, and water may burst from them like the icy rivers that emerge from the base of glaciers.

At such times, the stream appears black and lifeless and the sounds of fracturing and shifting ice may shatter the quiet of the valley. But with spring will come again the agreeable babbling of the brook and the cries of peepers.

A professor of mine once told our class that to be an effective geologist, one must have a good imagination — and this portion of Lower Flat Rock Road is an excellent stimulant to the mind.

Standing on its banks, one can imagine the crash of ancient seas transporting and depositing sediments and sea shells, the growth and grinding of glaciers during the Great Ice Age, and the relentless shaping and reshaping of the landscape and the labyrinths of the streambed as the Onesquethaw continues its unrelenting search for the sea.

Location:

The Enterprise — Mike Nardacci

Clarksville Cave is one of the most heavily-visited non-commercial caves in the Northeast; this is one of its historic entrances.

The Enterprise — Mike Nardacci

The entrance to Onesquethaw Cave is flooded. The cave lies in a low area and is subject to high water in times of heavy precipitation or snowmelt.

The Enterprise — Mike Nardacci

The rustic cabin in the Schoharie Caverns Nature Preserve is frequently used by college outdoor clubs and geology classes on field trips.

The Enterprise — Mike Nardacci

Situated at the base of a limestone cliff, the entrance to Schoharie Caverns leads to a high canyon passage richly decorated with calcite formations.

— Photo by Art Palmer

Knox Cave in winter has massive ice deposits cloaking its entrance. The photo was taken around 1960 when the staircase was still intact, but the scene looks much the same in any Helderberg winter.

— Photo by Mike Nardacci

The picturesque entrance to Spider Cave gives no hint of its uninviting interior though its name alludes to the creatures that populate its walls in great numbers.

 

The precise locations of the caves referred to in this column have been left deliberately vague to protect both the caves and inexperienced persons who might wish to enter them. Those interested in local cave exploration are urged to check out the website of the Northeastern Cave Conservancy — www.necaveconservancy.org — and to consider a cave trip tailored to their abilities during the period between May 1 and Sept. 30 when the caves are open to visitors.

One might — in a whimsical moment — regard it as “The Spelean Archipelago.”

Though sport — and scientific — cavers have long frowned upon the term “spelunker,” the noun “speleology” — the scientific name for the study of caves, derived from “spelaion,” the Greek word for a cave — and the adjective “speleological” have long been standard usage.

Across the United States, preserves in karst areas dot the map, ranging in size from a single acre to hundreds — karst” being the term for a region of limestone or marble bedrock containing caves. In our part of the country they are owned and/or managed by two organizations: the Northeastern Cave Conservancy, which recently celebrated its 40th anniversary, the website of which declares that its mission is the conservation, study, acquisition, and management of northeastern caves; and the National Speleological Society, today an international, organization of sport and scientific cave explorers.

The organizations are commonly referred to respectively as “the NCC” and “the NSS.” Their preserves protect numerous caves, the watersheds they involve, the unique life within them, and the classic karst surface features such as sinkholes, disappearing streams, and springs. Many local cavers are members of both organizations, the websites of which detail the history and geology of the various preserves.

From Oct. 1 to the end of April, many Northeastern caves — and all of those under the ownership or management of the NCC and the NSS — are closed to protect the caves’ bat populations, which in recent years have been ravaged by the insidious disease known as White Nose Syndrome.

Commercial caves such as Howe Caverns and a number of privately-owned caves that do not harbor bats remain open; however, winter has never been a very popular time for sport caving except for the most dedicated, given the fact that Northeast caves are almost by definition very wet, and slogging through snow in subfreezing temperatures to and from the caves can be extraordinarily miserable.

The National Speleological Society was founded in 1941 by a small but dedicated group of cave explorers and since has grown to an international organization with thousands of members. In the Northeast, the NSS owns three Schoharie County cave preserves: the Schoharie Caverns Nature Preserve; the James Gage Karst Preserve; and McFails cave, the most extensive in the Northeast. All three properties were donated to the NSS by generous patrons and have been maintained over the years by dedicated volunteers.

Knox Cave tragedy leads to stewardship

Yet the NCC was born as the final result of a tragic caving accident in 1975.

In May of that year, several college students from Albany were attempting to enter Knox Cave, which even late in the season still had a huge mass of ice encrusting the part of its sinkhole above the entrance.

The cave near the hamlet of Knox had sporadically been run as a commercial operation like Howe and Secret Caverns in Cobleskill, most famously under the ownership of Delevan C. Robinson and his wife, Ada. In the mid-20th Century, the couple were responsible for the building of an elaborate staircase offering access to the cave, which lies over 100 feet underground, and for constructing walkways and installing lighting for tourists.

D.C. seems to have had what the Irish call “the gift of blarney”: Some of his descriptions of the cave and its extent were — to put it gently — fanciful. But the cave features both large, easily-accessed passageways and more challenging sections that require stamina and sometimes ropework of explorers and it has attracted serious cavers for many generations as well as tourists during the relatively brief periods when it was commercialized.

The Robinsons also built a large roller rink adjacent to the cave’s entrance sinkhole that for a while, in the 1940s and 1950s, was the scene of skating parties and country dances. It seems to have formed a center of social life for the Hilltowns in the days when not many hardworking Helderberg folks could afford the time or the money to travel to nearby cities for entertainment.

But following D.C.’s death, commercial operation of the cave ended for the last time in 1961, though sport cavers and scientists continued to gain access to Knox with the kind permission of D.C.’s widow, Ada, until she died in 1964.

Some time in the mid-1960s, the largely abandoned property was purchased by a Long Island corporation called “Organa Industries,” which announced its intention to restore the cave and dig out a boulder-choked sinkhole adjacent to its classic entrance to allow a through trip. But Organa Industries went belly-up and the restorations never took place.

Old-timers in the Knox area may remember the huge steam shovel that stood for years in the field next to the commercial entrance but it seems never to have been employed in digging the clogged sinkhole and it eventually collapsed into a rusty pile of warped metal and cables.

The result was that access to Knox Cave was without any sort of control; in the years that followed, the staircase and the walkways deteriorated and the lighting system and many of the cave’s natural decorations were vandalized, and the skating rink and the Robinsons’ 200-year-old farmhouse were torched.

Even the massive frozen waterfalls that formed in winter from drainage in the fields around the Knox sinkhole did not deter visitors from entering the cave. Sometimes the warmer (48-degree) air within the cave would melt a tight hole allowing access to the adventurous — or risk-takers — while at other times the even more foolhardy were rumored to be using sledge hammers to smash their way through the ice to gain entrance.

In any case, one day in May 1975, as a group of Albany students tried to enter the cave through its ice-encrusted entrance, spring runoff from surrounding fields poured in a cascade behind the ice deposits.  The result was that a massive block of ice broke away and came crashing down, killing one student and leaving another paralyzed from the neck down.

By that time, the cave and surrounding land had been sold for non-payment of taxes to a doctor from Schenectady. Fearing additional injuries and lawsuits, the doctor attempted to donate the cave to the National Speleological Society. But the same fears caused the NSS to reject the offer, and a group of cavers became concerned that the cave might be acquired by someone who would ban all exploration or even bulldoze its entrance sinkhole effectively closing it permanently.

Thus, in 1978, three area men — Robert Addis, Dr. Art Palmer, and Jim Harbison — formed the Northeastern Cave Conservancy as a not-for-profit group and Knox Cave has continued to be made available to qualified cavers.

Over the years, subsequent exploration has added close to 1,000 feet of previously unknown passage to the map of Knox Cave and revealed another segment of passage yet to be connected to Knox known as Crossbones Cave. And, over the years, through purchase or donation, the NSS and the NCC have acquired a number of other parcels of land containing caves that are also well-known to explorers.

Caves galore

A western portion of the Helderberg Plateau known as Barton Hill in Schoharie County rises steeply above the Fox and Schoharie creeks. A standing joke among cavers is that the hill is hollow because of the numerous caves that underlie it.

One large parcel of land owned by the NSS was donated by the Gage family and contains the Schoharie Caverns, which resembles a slot canyon; its entrance lies at the base of a limestone cliff on the edge of the plateau.  Schoharie Caverns consists of nearly half a mile of streamway featuring beautiful stalactites and stalagmites that decades of visits by college outing clubs and other groups have left marvelously intact.

A rather spartan cabin on the property is maintained by local cavers and is available for groups visiting Schoharie Caverns and other nearby cave preserves.

And there are many. The NSS also owns another large parcel of land on Barton Hill known as the James Gage Karst Preserve; it contains Ball’s Cave, named after its 19th-Century landowner.

Its vertical entrance lies in a heavily-wooded section of the hill and has drawn visitors for over 150 years.  The cave features immense rooms as well as low crawl ways, and a diminutive flooded segment of the cave known as the “Lost Passage” requires cavers to experience a chilling “ear dip” to pass through it.  (Do you really want to ask?)

Although there are a number of other known or suspected caves on Barton Hill not under the control of the NSS or the NCC, Spider Cave was recently donated to the NCC by a local landowner. Its alluring entrance has been described as “Storybook,” but explorers have found that it is a very short story except for those with the intrepidity to challenge its agonizingly tight, wet main passage that extends for over a thousand miserable feet into the plateau.

And those who enter its easily accessible first hundred or so feet will encounter scores of its eponymous creepy occupants scampering across the cave’s water-smoothed walls.

McFails is the jewel

Generally considered the “jewel in the crown” of Northeast caves is McFails Cave on the Cobleskill Plateau. Its entrance is in a beautiful hemlock-and-hardwood forest pockmarked with gaping vertical sinkholes, some of which take voluminous quantities of water from time to time.

Only a short and very unpleasant segment of McFails was known until 1961 when some students from Cornell University plunged through a pool with only a few inches of airspace and discovered that the cave did not end at the uninviting pool. Today the cave is known to be over seven miles in length, much of which consists of high canyons and large chambers beautifully decorated with calcite formations.

But the cave can be treacherous: Entrance requires rappelling down 70 feet — in wet weather through a waterfall — and much of a cave trip involves constant immersion in a cold stream, making the wearing of a wetsuit a necessity. The cave has been hydrologically connected to other caves on the plateau, meaning that water in them them has been traced to McFails.

Thus the potential exists for a cave system some 26 miles in length — a fact likely to draw intrepid explorers for years to come.

Clarksville Cave is the best known

Undoubtedly the NCC-owned cave that is best known to the general public is Clarksville Cave, which has drawn visitors for well over 150 years. Groups from camps, schools, churches, and colleges regularly visit the cave between May 1 and Sept. 30.

Clarksville has three known entrances and lies beneath a hardwood forest laced with nature trails. While much of the cave consists of subway-tunnel size passages, more adventurous visitors are drawn to its tight — and wet — challenging sections that lead to pools and a picturesque waterfall.

Despite its easy accessibility and heavy traffic in summer months, much of the cave is relatively pristine and its numerous classic features both above and below ground make it a veritable textbook example of cave and karst geology.

Ominous Onesquethaw

Not far from the village of Clarksville is the lesser-known Onesquethaw Cave also owned by the NCC. Named for the stream that flows through the valley in which its entrance lies, its low, twisting passages are studded with fossils and its sometimes maze-like layout gives the cave a certain allure.

But Onesquethaw is not for the novice cave explorer and has long had a somewhat ominous reputation. It lies in a low area that is prone to flooding and, in times of sudden heavy precipitation, a roaring stream enters the cave and can fill its passages to the ceiling.

In 1991, a group of college students became briefly trapped in Onesquethaw when a torrential surge of water flooded the cave, setting off a massive rescue effort involving the Albany-Schoharie Cave Rescue group and local fire companies as well as news organizations from all over the Northeast.

The students had fortunately found a room with a high ceiling and were able to cling to the walls until the water levels finally dropped and allowed them to leave the cave.

As the students’ experience in Onesquethaw Cave demonstrates — the subterranean world demands respect of those who enter it. The Northeastern Cave Conservancy and the National Speleological Society have not only managed to acquire and keep open many classic Northeastern caves for qualified visitors, the groups have educational and scientific components as well.

Through work with the general public as well as scientists and qualified students, ranging from grade school right up through university-level, the organizations have helped to maintain and protect the resources of the world beneath our feet.

And the NCC and the NSS are not alone. All across the 48 contiguous States and in Alaska and Hawaii, many hundreds of acres of karst lands and areas underlain by lava caves have been acquired and protected by organizations of dedicated cavers — a “spelean archipelago” indeed.

Could statehood be far behind?

Location:

— Photo by Art Palmer

Knox Cave in winter has massive ice deposits cloaking its entrance. The photo was taken around 1960 when the staircase was still intact, but the scene looks much the same in any Helderberg winter.

— Photo by Mike Nardacci

The picturesque entrance to Spider Cave gives no hint of its uninviting interior though its name alludes to the creatures that populate its walls in great numbers.

The precise locations of the caves referred to in this column have been left deliberately vague to protect both the caves and inexperienced persons who might wish to enter them. Those interested in local cave exploration are urged to check out the website of the Northeast Cave Conservancy — www.necaveconservancy.org — and to consider a cave trip tailored to their abilities during the period between May 1 and Sept. 30 when the caves are open for visitors.

One might — in a whimsical moment — regard it as “The Spelean Archipelago.”

Though sport- and scientific-cavers have long frowned upon the term “spelunker,” the noun “speleology” — the scientific name for the study of caves, derived from “spelaion,” the Greek word for a cave — and the adjective “speleological” have long become standard usage.

Across the northeastern United States, preserves in karst areas dot the map, ranging in size from a single acre to hundreds — “karst” being the term for a region of limestone or marble bedrock containing caves.  They are owned and/or managed by two organizations known as the Northeast Cave Conservancy, which recently celebrated its 40th anniversary, and the National Speleological Society — commonly referred to respectively as “the NCC” and “the NSS.”

The preserves protect numerous caves, the watersheds they involve, the unique life within them, and the classic karst surface features such as sinkholes, disappearing streams, and springs. Many local cavers are members of both organizations, the websites of which detail the history and geology of the various preserves.

From May through September, the NCC also offers instructions on access to the caves for the qualified public. From Oct. 1 to the end of April, many Northeastern caves — and all of those under the ownership or management of the NCC and NSS — are closed to protect the caves’ bat populations, which in recent years have been ravaged by the insidious disease known as “White Nose Syndrome,” or “WNS.”

Commercial caves such as Howe Caverns and a number of privately-owned caves that do not harbor bats remain open; however, winter has never been a very popular time for sport caving except for the most dedicated cavers, given the fact that Northeast caves are almost by definition very wet, and slogging through snow in sub-freezing temperatures to and from the caves can be extraordinarily miserable.

The National Speleological Society was founded in 1941 by a small but dedicated group of cave explorers and since has grown to become an international organization with thousands of members. In the Northeast, the NSS owns three Schoharie County cave preserves: Schoharie Caverns, the Gage Preserve, and McFails Cave, the most extensive in the Northeast. All three properties were donated to the NSS by generous patrons and have been maintained over the years by dedicated volunteers.

Knox Cave tragedy leads to stewardship

Yet the NCC was born as the final result of a tragic winter caving accident in 1975.

In March of that year, several students from the State University of New York Outing Club were attempting to enter Knox Cave through its ice-encrusted sinkhole.

The cave near the hamlet of Knox had sporadically been run as a commercial operation like Howe and Secret Caverns in Cobleskill, most famously under the ownership of Delevan C. Robinson and his wife, Ada. In the mid-20th Century, the couple were responsible for the building of an elaborate staircase offering access to the cave, which lies over 100 feet underground, and for constructing walkways and installing lighting for tourists.

D.C. seems to have had what the Irish call “the gift of blarney,” and some of his descriptions of the cave and its extent were — to put it gently — fanciful. But the cave features both large, easily-accessed passageways and more challenging sections that require stamina and sometimes ropework of explorers, and it has attracted serious cavers for many generations as well as tourists during the relatively brief periods when it was commercialized.

The Robinsons also built a large roller rink adjacent to the cave’s entrance sinkhole, which for a while in the 1940s and 1950s was the scene of skating parties and country dances. It seems to have formed a center of social life for the Hilltowns in the days when not many hardworking Helderberg folks could afford the time or the money to travel to nearby cities for entertainment.

But following D.C.’s death in 1961, commercial operation of the cave ended for the last time though sport cavers and scientists continued to gain access to Knox Cave with the kind permission of D.C.’s widow until she died in 1964.

Some time in the mid-1960s, the largely abandoned property was purchased by a Long Island corporation called “Organa Industries,” which announced its intention to restore the cave and dig out a boulder-choked sinkhole adjacent to its classic entrance to allow a through trip.  But Organa Industries went belly-up and the restorations never took place.

Old-timers in the Knox area may remember the huge steam shovel that stood for years in the field next to the commercial entrance but it seems never to have been employed in digging the clogged sinkhole and it eventually collapsed into a rusty pile of warped metal and cables.

The result was that access to Knox Cave was without any sort of control; in the years that followed, the staircase and the walkways deteriorated and the lighting system and many of the cave’s natural decorations were vandalized and the skating rink and the Robinsons’ 200-year-old farmhouse were torched.

Even the massive frozen waterfalls that formed in winter from drainage in the fields around the Knox sinkhole did not deter visitors from entering the cave. Sometimes the warmer (48-degree) air within the cave would melt a tight hole allowing access to the adventurous — or risk-takers — while at other times the even more foolhardy were rumored to be using sledge hammers to smash their way through the ice to gain entrance.

In any case, one day in March, 1975, although snow still covered the ground, the temperature rose to 50 degrees as a group of students from SUNY Albany tried to enter the cave. Runoff from the melting snow poured in a cascade behind the ice deposits and the result was that a massive block of ice broke away and came crashing down, killing one student and leaving another paralyzed from the neck down.

By that time, the cave and surrounding land had been sold for non-payment of taxes to a doctor from Schenectady. Fearing additional injuries and lawsuits, the doctor attempted to donate the cave to the National Speleological Society.

But the same fears caused the NSS to reject the offer and a group of cavers became concerned that the cave might be acquired by someone who would ban all exploration or even bulldoze its entrance sinkhole, effectively closing it permanently.

Thus, in 1978, three area men — Dr. Art Palmer, Robert Addis, and Jim Harbison — formed the Northeast Cave Conservancy as a not-for-profit corporation and Knox Cave has continued to be made available to qualified cavers. Over the years, subsequent exploration has added close to 1,000 feet of previously unknown passage to the map of Knox Cave and revealed another segment of passage yet to be connected to Knox known as Crossbones Cave.

And over the years, through purchase or donation, the Northeast Cave Conservancy has acquired a number of other parcels of land containing caves that are also well-known to explorers.

Caves galore

A western portion of the Helderberg Plateau known as Barton Hill in Schoharie County rises steeply above the Fox and Schoharie creeks. A standing joke among cavers is that the hill is hollow because of the numerous caves that underlie it.

One large parcel of land owned by the NSS was donated by long-time caver and local attorney Jim Gage and contains Schoharie Caverns, which resembles a slot canyon; its entrance lies at the base of a limestone cliff on the edge of the plateau.

Schoharie Caverns consists of nearly half-a-mile of streamway featuring beautiful stalactites and stalagmites, which decades of visits by college outing clubs and other groups have left marvelously intact.  A spartan cabin on the parcel is maintained by local cavers and is available for groups visiting Schoharie Caverns and other nearby cave preserves.

And there are many. The NSS also owns another large parcel of land on Barton Hill donated by Jim Gage and named in his honor; it contains Ball’s Cave, named after its 19th-Century landowner. Its vertical entrance lies in a heavily-wooded section of the hill and has drawn visitors for over 150 years.

The cave features immense rooms as well as low crawl ways, and a diminutive flooded segment of the cave known as the “Lost Passage” requires cavers to experience an “ear dip” to pass through it. (Do you really want to ask?)

Although there are a number of other known or suspected caves on Barton Hill not under the control of the NSS or NCC, Spider Cave was recently donated to the NCC by a local landowner.  ts alluring entrance has been described as “Storybook,” but explorers have found that it is a very short story except for those intrepid enough to challenge its agonizingly tight, wet main passage that extends for over 1,000 miserable feet into the plateau. And those who enter its easily accessible first hundred-or-so feet will encounter hundreds of its eponymous creepy occupants scampering across the cave’s water-smoothed walls.

McFails is the jewel

Generally considered the “jewel in the crown” of northeast caves is McFails Cave on the Cobleskill Plateau. Its entrance is in a beautiful hemlock and hardwood forest pockmarked with gaping vertical sinkholes, some of which take voluminous quantities of water from time to time.

Only a short and very unpleasant segment of McFails was known until 1961 when some students from Cornell University plunged through a pool with just a few inches of airspace and discovered that the cave did not end at the uninviting pool.

Today the cave is known to be over seven miles in length, much of which consists of high canyons and large chambers beautifully decorated with calcite formations. But the cave can be treacherous: Entrance requires rappelling down seventy feet — in wet weather through a waterfall — and much of a cave trip involves constant immersion in a cold stream, making the wearing of a wetsuit a necessity.

The cave has been hydrologically connected to other caves on the plateau, meaning that water in them them has been traced to McFails. Thus the potential exists for a cave system some 26 miles in length — a fact likely to draw intrepid explorers for years to come.

Clarksville Cave is the best known

Undoubtedly the NCC-owned cave that is best known to the general public is Clarksville Cave, which has drawn visitors for well over 150 years. Groups from camps, schools, churches, and colleges regularly visit the cave between May 1 and Sept. 30.

Clarksville has three known entrances and lies beneath a hardwood forest laced with nature trails. While much of the cave consists of subway-tunnel size passages, more adventurous visitors are drawn to its tight — and wet — challenging sections that lead to pools and a picturesque waterfall.

Despite its easy accessibility and heavy traffic in summer months, much of the cave is relatively pristine and its numerous classic features both above and below ground make it a veritable textbook example of cave and karst geology.

Ominous Onesquethaw

Not far from the village of Clarksville is the lesser-known Onesquethaw Cave also owned by the NCC.  Named for the stream that flows through the valley in which its entrance lies, its low, twisting passages are studded with fossils and its sometimes maze-like layout gives the cave a certain allure.

But Onesquethaw is not for the novice cave explorer and has long had a somewhat ominous reputation.   It lies in a low area that is prone to flooding and in times of sudden heavy precipitation a roaring stream enters the cave and can fill its passages to the ceiling.

In 1991, a group of students from Syracuse University became briefly trapped in Onesquethaw when a torrential surge of water flooded the cave, setting off a massive rescue effort that drew news organizations and cave-rescue teams from all over the Northeast. The students had fortunately found a room with a high ceiling and were able to cling to the walls until the water levels finally dropped and allowed them to leave the cave.

As the students’ experience in Onesquethaw Cave demonstrates, the subterranean world demands respect of those who enter it. The Northeast Cave Conservancy and the National Speleological Society have not only managed to acquire and keep open many classic Northeastern caves for qualified visitors, they have educational and scientific components as well.

Through work with the general public as well as scientists and qualified students, ranging from grade school right up through university-level students, the organizations have helped to maintain and protect the resources of the world beneath our feet.

And the NCC and NSS are not alone. All across the 48 contiguous states and in Hawaii many hundreds of acres of karst lands and areas underlain by lava caves have been acquired and protected by organizations of dedicated cavers: a “spelean archipelago” indeed.

Could statehood be far behind?

Location:

— Photo by Mike Nardacci

Heavily eroded petrified dunes in the Bisti wilderness show cross bedding. Almost identical features have been found in Gale Crater on Mars.

— Photo by Mike Nardacci

These mudstone and sandstone hills in the Bisti wilderness exhibit layers colored by various minerals deposited in an ancient inland sea.

— Photo by Mike Nardacci

A maze of weirdly-shaped hoodoos were created by the erosion of rock layers with varying resistance to the actions of wind, running water, and frost.

— Photo by Mike Nardacci

Cirrus clouds made of ice crystals waft high in the atmosphere above the Bisti wilderness. Similar clouds have been photographed on Mars by the Curiosity rover.

— Photo by Mike Nardacci

Rounded hills in Gale Crater on Mars are made of sediments similar to those in the bedrock of the Bisti/De-Na-Zin wilderness.

The Bisti/De-Na-Zin wilderness in the northwest corner of New Mexico is hot and dry for much of the year — when it is not bitter cold and dry — and it is far from the regions that are well-known to tourists such as those surrounding the cities of Santa Fe, Albuquerque, and Taos.

Even some of the draws for the more adventurous visitor — the “Sky City” Pueblo called Acoma, the stunning ancient Anasazi ruins of Chaco Canyon, and artist Georgia O’Keefe’s beloved Ghost Ranch — are far better known and more accessible than the Bisti/De-Na-Zin Badlands.  Perhaps due to a recent article with photographs in “New Mexico” magazine, the public has become more widely aware of the preserve but the location’s remoteness virtually guarantees that even on weekends hikers are likely to find few others venturing into the barren wilderness.

The term “badlands” was coined by non-geologists but has been appropriated by geologists to describe an area featuring an exceedingly arid climate and relatively soft bedrock that has eroded into hills and sometimes weird sculptured shapes called “hoodoos.” Practically nothing can grow in badlands and even creatures such as insects, lizards, and snakes may be rare.

The Badlands of South Dakota became a national park because of the particularly colorful strata — layers — found there but large stretches of the United States Southwest and many other places scattered across Earth’s surface are badlands in fact if not always in name.

Geologists have always had great interest in badlands because in such barren landscapes — unlike in the well-watered, forest-and-field-covered stretches of the Northeast — the underlying bedrock lies open to easy viewing, and, where wind, ice, and water have worked on the bedrock, researchers can see deeply into the strata to find hidden clues to ancient environments.

The Bisti/De-Na-Zin badlands lie southeast of Farmington, New Mexico. The words are Navajo;  “Bisti” translates to something like “large area of shale hills,” which perfectly describes it. “De Na Zin” references falcons, seen occasionally in the wilderness area.

Its soft bedrock is mainly shale and mudstone interspersed with volcanic dust dating from the Cenozoic Era, the age of the dinosaurs. Its eroding hills and hoodoos have yielded numerous fossils of dinosaurs and other creatures that were their contemporaries as well as plants.

The strata that make up the bedrock contain varying amounts of minerals such as iron, carbon, magnesium, and quartz, which give them different colors: black, white, gray, purple, brown, and in some striking examples, bright rusty red. The strata were laid down in what in ancient times was a delta on the edge of the long-vanished Western Interior Seaway and the purple layers get their color from iron dissolved in the water.

While most of the brown strata are mudstone, the black strata are either shale containing decayed organic matter or soft coal; at some point in ancient times, the coal caught fire, possibly due to nearby volcanic activity. In any case, there is evidence that the fires burned underground for centuries, leaving behind a brilliantly red layer that erodes into piles of rust-colored sand and what appear to be crushed bricks.

An adventure

With some friends, I set off on a hike into the Bisti/De-Na-Zin badlands on a warm day in early June.  Hikers are advised to carry a device with GPS or a compass as the preserve does not have marked trails and landmarks can be deceiving, but we did observe a line of abandoned telephone poles that ran close to the primitive parking area.

Fortunately, given the gentleness of the topography, the poles were visible from great distances, providing us with easily visible reference points as the mazes of gullies and hoodoos of Bisti would not be good places in which to lose one’s way.

We set off over a series of low hills made of crumbling soft coal — a lifeless wasteland that looked like a landscape of Mordor in Tolkien’s Lord of the Rings — an uninviting beginning to a hike that gave no clue to what lay beyond.

Soon we climbed up out of the coal-bearing strata and found ourselves among the eroded fragments of ancient sand dunes, showing characteristic structures called “cross-bedding,” evidence of deposits caused by shifting water currents. In such locations, paleontologists sometimes find the footprints of late-Mesozoic dinosaurs.

Our map showed a great cluster of hoodoos half a mile or so away and we set off in a southerly direction. Soon we came upon a series of garishly-striped hills into which were eroded steep, narrow gullies — miniature slot canyons formed by the region’s occasional but torrential floods. On higher ground now, we could look across a wide, broad valley into which the sediments eroded off the Bisti hills have been settling for millions of years.

There were domes and small mesas, wide arroyos and narrow gullies, towering hoodoos, balancing rocks, and small erosive features resembling tables, turtles, barstools, and weirdly organic-looking forms suggestive of creatures out of some scary fairytale.

We climbed to a vantage point, a low flat-topped hill from which we could look down into a bewildering maze in which many of these sculpted features were clustered together. Nearby, and scattered randomly, projecting from the baked ground beneath our feet were fossilized stumps of Mesozoic-age trees that might once have offered shade to a dinosaur.

Though the air temperature was only in the low 80s, the sun overhead shone out of a sky swept with high, feathery cirrus clouds; the air was clear but for the thin haze caused by one of the Southwest’s forest fires that have been frequent this year. Though the scene before us was not without a stark beauty, it also seemed absolutely barren of life — and yet, from time to time a dusty-colored lizard would scamper across our paths and there were a few parched-looking cactuses and other desert plants.

The Bisti wilderness is also home to a number of golden eagles, hawks, and falcons but the occasional birds we could see soaring on updrafts above the baking ground were too far away for identification. In Jeff Goldblum’s iconic phrase from Jurassic Park — “Life will find a way.”

Like Mars

Some photographs sent back recently by the National Aeronautics and Space Administration’s “Curiosity” rover, which is currently climbing through the terrain of Gale Crater near the equator of Mars have demonstrated that the Red Planet, too, has its badlands.

The first blurry photographs of Mars returned by the Mariner 4 spacecraft in 1965 appeared to show what Carl Sagan called “a dull, uninteresting landscape” — all sand dunes and flat deserts like “Tatooine” in the “Star Wars” films, but subsequent probes showed that by very bad luck Mariner had missed vast stretches of Mars with complex, fascinating landscapes, including a spectacular canyon seven times deeper and 10 times longer than our own Grand Canyon.

In addition, photos of dried stream beds and river channels hundreds of miles long proved that the planet once had enormous amounts of flowing water — an absolute necessity for life as we know it.

Gale Crater was created eons ago when an asteroid crashed into the surface and the subsequent rebound of the bedrock thrust up an enormous peak called Mount Sharpe. The Curiosity rover began exploring the crater in 2011 and early on in its mission it sent back a photograph of the upthrust bedrock that shows a startling resemblance to some of the layered, eroded hills of the Bisti badlands.

The hills in Gale Crater have been found to be made of bedrock resembling shales and sandstones, interspersed with layers of volcanic dust — very similar to those in the Bisti wilderness and providing clues to the ancient environment of Mars. Cruising around the floor of the ancient crater, Curiosity has also analyzed numbers of heavily eroded hoodoos composed of cross-bedded sandstone.

These are evidence that the great crater was once filled with salty water with shifting currents that deposited the sand that was later turned to stone. Elsewhere the rover has photographed channels filled with rounded pebbles, the beds of ancient streams that flowed across the surface.

Today the Martian atmosphere is far too thin and cold to allow liquid water to remain on the surface for long without evaporating or freezing. But just as the hills of badlands such as Bisti/De-Na-Zin give scientists clues to the ancient environments of Earth, the eerily similar hills of Gale Crater give insight into the ancient past of Mars, and what they show is far different from what was inferred in the 1960s from those first, blurry images of the Martian surface.

The planet’s landscape is anything but “dull and uninteresting” and evidence shows that in the distant past, Mars was a warmer, wetter world with a thick atmosphere, and featured extensive bodies of salty water as well as rivers. In such a world life could have flourished.

But the surface today is devoid of anything living, subjected endlessly to ultraviolet radiation from the sun because of Mars’s thin atmosphere, and not a blade of desert grass nor dusty, stunted shrub is visible in the blasted landscape.

Eerily, the thin clouds that appear in Curiosity’s photographs are almost identical to those above the Bisti/De-Na-Zin wilderness: wispy feathery cirrus clouds formed from crystals of water ice high in the Martian atmosphere.

But, unlike the milky blue sky above New Mexico, the sky on Mars is a dusty yellow from tiny dust particles suspended in the atmosphere high above the surface by the planet’s winds. Sampling that atmosphere, Curiosity not long ago made a tantalizing detection: The cyclical presence in the atmosphere of quantities of methane.

The colorless, odorless gas is easily destroyed by ultraviolet light, and the atmosphere of Mars today is far too thin to prevent its destruction, meaning that the gas must constantly be replaced. While methane can be emitted during volcanic activity, the giant shield volcanoes on Mars appear to have been inactive for millions of years.

But methane is also a common waste product of biologic activity. Curiosity has found that in the relatively warmer months in Gale Crater the amount of methane increases and then levels off and falls as the climate gets colder. The possibility that this could be indicative of the activity of sub-surface primitive organisms has thus arisen.

Though relatively benign by comparison, the harsh climate of the Bisti/De-Na-Zin wilderness supports the existence of a few hardy forms of plants and animals, while the environment of Mars today is hostile in the extreme to living things. The thin air contains almost no oxygen and the dry, bitterly cold, barren landscape is constantly blasted by lethal radiation from the sun.

But the fact that Mars in distant ages was apparently much friendlier to life — if life ever arose there — gives hope that a few hardy organisms might have found refuge in a warmer, wetter, protected environment underground. Life, after all, is well known for “finding a way.”

Location:

— Photo by Mike Nardacci

Massive, intricately-carved stone walls in the citadel of Sacsayhuaman dwarf visitors. Some of the boulders weigh upwards of 90 tons and their shapes are believed to make the walls resistant to earthquakes.

— Photo by Mike Nardacci

Terraces: The citadel of Ollantaytambo in the Sacred Valley of the Incas was the site of one of the few battles lost by the Conquistadors as they swept through the Incan empire.

— Photo by Mike Nardacci

A view from the train that transports visitors to Machu Picchu through the Sacred Valley shows the towering Andes peaks are covered in snowfields and glaciers; the melt-water eventually reaches the Amazon River.

— Photo by Mike Nardacci

Rapids of the Vilcanota River flows through the village of Aguas Calientes. Downstream, it becomes known as the Urumbaba River and eventually is a tributary to the Amazon.

Is it possible that Number 5 could be printed larger than the others?

— Photo by Mike Nardacci

The classic view of the citadel of Machu Picchu, showing granite walls and terraces that sprawl beneath Pyramid Mountain on which a dizzying rail ascends to a Sun temple on the summit.

— Photo by Mike Nardacci

Mountains surround Machu Picchu and, from the deep valley of the Vilcanota River, mists rise, cloaking the site at times in a mystical aura.

The engineering achievements of the ancients astound us: The vast size and precision of the Egyptian pyramids, the extraordinary aqueducts of the Romans, the incredible invention of Greek temples such as the Parthenon, the environmental challenges overcome by the people of Southeast Asia to build the Great Wall in China and Angkor Wat in Cambodia, the extensive waterworks and massive temples of the Maya and the Aztecs — all continue to amaze and enthrall in spite of our own achievements using modern technology.

It is no wonder that some today deride the ancient people with assertions that they could not have achieved what they did without help from Out There and continue to claim evidence of extraterrestrial intervention from the star Sirius or some civilization with its home on one of the stars in the belt of Orion.

But a scientist friend of mine put the whole situation into perspective with this observation: “These so-called ‘researchers’ are telling us that beings with the technology to fly faster than light across the universe visited Earth in the distant past — and spent their time here showing ancient people how to cut and pile up rocks? After a journey like that, wouldn’t it have been more productive to teach our ancestors how to make penicillin? Or instruct them in the generation of electricity and the building of computers?  Or show them something as simple but essential as the wheel, which many of them did not have?”

It is a fact that the ancient people had brains as big and complex as ours today and when they wanted to do something badly enough, they often figured out ingenious ways to do it without help from E.T.  And we moderns frequently stand in absolute awe of what they accomplished using technology that we all too frequently brand “primitive.”

Early in April, I flew to Peru with friends to visit some of the major sites of the Incas. Since we had very limited time, we had booked one of those hectic if-it’s-Tuesday-this-must-be-Cusco vacations, the result being that the whole trip now seems like something I dreamed and I look upon the photos I took with that did-I-really-go-there sense of wonder and confusion.

Bu,t if the confusion is genuine, so is the wonder: at the incredible beauty of the Andes Mountains rising above lush but intimidating jungle; at the clash of the Incan and Spanish civilizations that gave birth to the mestizo (“mixed”) culture of modern Peru; and at the astounding architecture of the Incan peoples over 500 years ago that resulted in the construction of citadels such as Machu Picchu and other “lost” cities.

We began our trip with a very brief stay in Lima, Peru’s vibrant capital city, built atop thick layers of unconsolidated river sediments washed down from the Andes over millennia — the consequent instability of which makes the city a dangerous place to be during an earthquake: a subject, perhaps, of a future Back Roads Geology column.

Early on our second day there, we boarded a plane for a short flight to Cusco — also spelled “Cuzco”— an ancient center of the Incan Empire situated at an elevation of 10,000 feet in the Andes. Spanish conquerors did a rather thorough job of destroying the Incas’ “pagan” buildings but in many places the colonial-era palaces and churches they raised were situated on those buildings’ foundations.

Cusco is today a sprawling city, overflowing with tourists even in what is considered its low season — but their presence has ignited the city’s economy and much of the Old City is one immense traffic jam.  Coupled with the elevation, the exhaust from motor vehicles makes breathing a challenge for those who have not acclimatized — which included many people such as ourselves who were there only briefly as Cusco is the jumping-off point for visitors bound for Machu Picchu.

The chewing of leaves from the coca plant is supposed to aid in alleviating the effects of altitude, and it seemed as if every hotel and restaurant offered patrons huge bowls of the dried leaves that they were encouraged to chew, or cups of tea made from coca leaves. I found the leaves to have a rather unpleasant flavor and, though the tea served with sugar was slightly more agreeable, any effect that the coca is alleged to have eluded me.

Sacsayhuaman

Much of our one full afternoon in Cusco was spent at the ruins of one of the citadels of the ancient Incan emperors called “Sacsayhuaman,” sprawled atop a flat hill high above the city. Our guide laughingly informed us that, although the name is almost unpronounceable to anyone not fluent in the Incan language — still spoken by many inhabitants of Peru—saying “sexy woman” gives a fair approximation.

Levity aside, even in ruins, the site inspires admiration for its builders. A stronghold of Pachacutec, one of the last of the Incan emperors, the site consists today of a series of formidable stone walls and terraces covering many acres, cut from the plateau’s limestone bedrock.

Though it is difficult to envision what it looked like in the days before it was largely leveled by the Spanish conquistadors, shaping and moving the massive carved boulders that make up the foundations and walls of the various structures would challenge 21st-Century engineers. Some of these limestone blocks weight upwards of ninety tons.

The awareness that the Incan builders accomplished this work with muscle power and simple tools alone astounds. Not only are the seams between the boulders tight enough that a knife blade cannot fit into them, the individual boulders themselves are often not cubic or rectangular.

Some of the huge blocks have slightly curved sides and, instead of having eight corners, may have as many as 14 or 16, showing that they were shaped with consummate skill. Current archaeological theory is that these intricate, tight-fitting shapes made the buildings resistant to earthquakes, a constant danger in Peru’s seismically-active landscape.

And indeed — in Lima and Cusco and other Peruvian cities, Colonial-era churches and palaces that were built on the foundations of razed Incan buildings have ridden out tremors with considerably less damage than structures around them lacking such foundations. Of course, millennia earlier, the ancient Egyptians also moved immense blocks and fitted them with uncanny precision, but the huge stones with which the Giza Pyramids were constructed are cubic or rectangular and have just eight corners.

Sadly, besides the massive walls and terraces, little else remains at Sacsayhuaman to testify to the extraordinary engineering skills of the Incas.

Sacred Valley of the Incas

The next day, the sky was gray with low, scudding clouds, and early in the morning we embarked by van up over the mountains surrounding Cusco, headed for what is romantically named the Sacred Valley of the Incas.

Getting there first required a steep climb up narrow, twisting roads followed by a descent of several thousand feet, all the while passing through green, terraced fields in which men and women in traditional Andean dress labored among crops and herds of sheep and llamas — pronounced “yamas” in Peru.

Before starting the descent, we paused at an overlook that presented a heart-stopping view of the switchbacks plunging into the valley and our first look at the high Andes. As the sky was overcast, the view was sketchy — but far off through breaks in the clouds were glimpses of glaciers and jagged, snow-covered peaks rising out of the mists that hung on the precipitous green slopes: It seemed a vision of the Himalayas.

In the afternoon, we climbed the ruins of the enormous Inca citadel called Ollantaytambo, site of one of the few defeats suffered by the Spaniards as they fought their way through the Sacred Valley. Situated between two steep mountains, it consists of a residential area on the floor of the valley and a series of massive terraces like giant steps ascending one of the slopes, accessed only by two narrow stone staircases.

The terraces served both as gardens and fortifications, and atop the slope is a broad platform with a temple. It is not difficult to understand why the Spanish conquerors were unable to take the fortress: The defending Incas had gravity on their side and were able to rain down crushing boulders onto the invaders.

The platform sits atop precipitous cliffs dropping a hundred feet or more, and tightly fit into the tops of the cliffs are stone walls consisting of the characteristic enormous, meticulously-shaped boulders.  Constructing the walls must have been a daunting challenge — one misstep on the part of the workers shaping and placing the boulders would have resulted in a deadly fall, undoubtedly accompanied by the thunderous collapse of sections of the wall as well.

Once again a visitor stands in awe of the Incas’ determination and skills.

Jungle journey

Early the next morning, we were deposited at the train station in the little town also called Ollantaytambo and we boarded the dome train that transports visitors through the jungles of the Sacred Valley to the village of Aguas Calientes, close to the citadel of Machu Picchu.

The 80-minute trip follows the ancient Inca Trail and the furiously-rushing Vilcanota River that downstream changes its name to the Urumbaba and eventually becomes a tributary to the Amazon.

The trip must be one of the most scenic train rides in the world. Heading toward Machu Picchu, on the right side of the cars passengers have a close-up view of the jungle which seems at any moment about to engulf the tracks.

It is a tangle of towering trees casting the floor into semi-darkness in which glimpses can be had of white, pink, and yellow orchids and other tropical flowers growing among shrubs and enormous ferns. But like giant entangling spider webs, vines thick and thin connect the trees and would make passage through the jungle a nightmare, even with machetes.

Occasionally visible through breaks in the foliage was the ancient Inca Trail that follows a narrow path through the jungle; it is a popular four-day hike for the adventurous visitor willing to challenge the biting insects and venomous snakes but in many places it was obvious that a hiker could be less than 50 feet from the train tracks or the trail itself and become hopelessly lost in the strangling vegetation.

Frequently there are foaming brooks and cascades pouring down from the high surrounding mountains, their waters bound for the Vilcanota and eventually joining the dark, meandering stretches of the Amazon.

And yet, despite the feeling generated of being in an endless, remote wilderness, periodically the train passes through areas on the far bank of the Vilcanota where archaeologists have cleared away the invading jungle and uncovered remote Inca settlements consisting of the characteristic terraces and foundations of dwellings, abandoned hundreds of years ago as the conquistadors marched ever deeper into the vastness of the Incan empire.

In other places, the jungle suddenly retreats and is replaced by a wide stretch of the valley floor that is being farmed or mined today by hardy descendants of the Incas; here the scene suddenly opens up to allow through the dome of the car breathtaking views of the high Andes: dark, craggy peaks in silhouette against the clouds or broad snowfields and glaciers gleaming in the brilliant sunlight, once more irresistibly evoking the landscapes of the Himalayas.

Ring of Fire

Shortly before noon, we arrived in the tiny picturesque village of Aguas Calientes — “hot waters” in translation. The village rises steeply above the eastern bank of the Vilcanota River, which descends energetically past the village in a series of roaring cascades and plunge pools.

A hot spring near the village has attracted bathers for hundreds of years. There are no volcanoes in the area, but the Andes Mountains rose — and continue to rise — as a result of the interaction of two of Earth’s major tectonic plates: the Nazca plate and the South American Plate, and the interface between them constitutes a section of the Pacific “Ring of Fire.”

The Nazca Plate takes up a large section of the Eastern Pacific Ocean and it is being pushed up against and subducting beneath the South American Plate; this causes the South American Plate to crumple, forming the Andes, but the friction caused by the subducting Nazca Plate melts parts of the crust and the molten rock rises to the surface and explodes in volcanoes. The presence of the hot springs in Aguas Calientes indicates the presence of molten rock not far beneath the surface.

In search of Vitcos

Immediately on leaving the train, we were escorted to a bus which takes visitors up a series of sharp and exposed switchbacks to the plateau on which Machu Picchu lies. It is a hair-raising ascent through the jungle with one 180-degree turn after another — and of course, there are no guard rails.

On some turns, passengers on one side of the bus or the other literally can see no road beneath them as they look out the windows but instead are staring straight down a plunge of hundreds of feet into the deep, rocky gorge of the Vilcanota River.

Along the way, the road frequently intersects one of several steep stone staircases that slice through the jungle and in ancient days offered the only access to Machu Picchu; these made the site virtually impregnable — even if the conquistadors had learned of its location — which they never did.

In fact, although rumors of its existence had been widespread for centuries, except for a few hardy farmers in the area, the rest of the world — including most Peruvians — remained unaware of its existence until 1911 when an expedition sponsored by Yale University and the National Geographic Society led by Hiram Bingham discovered it with the aid of some of those farmers.

Many explorers before him had been searching for the gold of the Incas that had not been appropriated by the conquistadors — and they had taken incredible amounts of the precious metal from Incan temples and shrines.

The interiors of the great cathedrals on the central squares of Cusco and Lima and other Peruvian cities are decorated with jaw-dropping quantities of gold, giving them a truly ethereal glow. But legends have persisted for hundreds of years that, as the Spanish conquerors swept through Peru, the forewarned Incas secreted much of their gold in places that have yet to be discovered  — a powerful lure to adventurers even today.

However, Bingham and the Yale expedition were not looking for the vanished Incan gold: They were in search of Vitcos, the fortress that was considered to be the capital of the Incan empire.

Questioning occupants of one of the small villages scattered along the Vilcanota River, they learned that some of the farmers had been working ancient terraces on top of a nearby peak known as “Machu Picchu” — Incan for “old mountain.”

Machu Picchu

Ascending the peak by way of one of the ancient trails, Bingham and his crew came upon the hidden fortress. Though the jungle masked most of the magnificent site, the expedition cleared enough to be aware that they had made a major discovery. Today, with much of the vegetation cleared away, the magnificence of the site has been revealed.  

Quarried from the granite bedrock of the mountain, the site sprawls over hundreds of acres, and there are still sections that lie under the suffocating jungle awaiting excavation. One of the most common igneous rocks on Earth, granite is frequently found in mountain ranges and makes up much of the bedrock of the continents.

Among its major constituents is the mineral feldspar, which can come in many colors ranging from gray or white to pink, rose, red, or purple. It is a very hard rock — harder by far than limestone — and not only did the Incas prize it as a decorative building stone but so did the Egyptians and other ancient cultures. Its hardness makes it difficult to work and inspires admiration for the people who carved it with such precision.

Today the site is believed to have been a retreat for the emperor Pachacutec, and everywhere are the foundations of private homes, temples, and what might have been palaces for the emperor and his retinue.  These structures are situated on flat stretches of ground between the great terraces, which were used both for farming and for defense and, as in other Incan sites, are all interconnected by a series of steep stone steps.

Seeing them, one has the thought that the Incan people must have had exceptionally strong legs, accustomed as they were to climbing up or down constantly!

There are several springs in Machu Picchu and their waters were fed into channels that provided irrigation for crops in the terraces, drinking water, and fountains all over the site. But the terraces did not have to serve for defense as the conquistadors never discovered Machu Picchu — indeed, they probably never even knew it existed.

And, in any case, given the fact that the only access to the site is by way of the precipitous stone staircases that ascend from the Vilcanota River valley, an invasion or siege with the military technology available to the conquistadors would have been next to impossible.

As impressive as Machu Picchu is for the engineering that went into its construction, it is undoubtedly its physical setting that has made it an item high on every traveler’s bucket list as well as a source of misguided mysticism.

The citadel is surrounded by high jungle-covered mountains with sheer granite cliffs plunging thousands of feet to the Vilcanota River valley, up and over which drift the mists which give the site its mystical appearance.

Moreover, draped in tropical vegetation a jagged peak — described in all the guidebooks as “iconic” — looms over the site just as the pyramids of the Maya and Aztecs and Egyptians towered over their cities.  It is not surprising to learn that it is in fact named “Pyramid Mountain”; it features a vertiginous trail sliced from the granite to its summit where there is a small temple to the Sun, the focus of Incan cosmology. One could be forgiven for thinking that even a Wal-Mart built in such a setting would inspire awe.

Archeologists today estimate that, in its heyday, Machu Picchu could have been home to as many as 6,000 people and provided a refuge for the emperors from the Spanish invaders. Given its remoteness and the difficulty of accession, it is easy to believe that many of the ancient people must have lived out their entire lives in the city.

It had a moderate climate, a steady and abundant supply of water, fertile ground for growing crops, an endless supply of building stone, and views that are ever-changing and provide constant inspiration for the Incans’ religious connection with Creation.

Mysteries remain

And reports have begun to surface that in the vegetation-cloaked mountains surrounding Machu Picchu, explorers have in recent years uncovered evidence of two more “lost” Incan citadels — one that has four times the area of Machu Picchu and one with six times its area. Clearly, the dense jungles of the Peruvian Andes hold many secrets yet.

It is sad to realize that many visit Machu Picchu because they see it as having some New Age connection to extraterrestrials or crystal energy — a fact confirmed by the presence in the tiny village of Aguas Calientes of so many head shops, tattoo parlors, and psychics, and the drifting odor of marijuana.

For the fact remains that Machu Picchu and the other great citadels of the Incas with their massive, intricately-shaped building stones and their many other astonishing feats of engineering are monuments to human ingenuity: with the simplest of tools and sufficient determination, the ancient Incan peoples were capable of achievements that can inspire admiration and awe even amid the technological marvels of the 21st Century.

Location:

— Photo by Steve Rider

A lower section of the steep Bright Angel trail is covered with slippery wind-blown sand.

— Photo by Steve Rider

Cottonwood trees are watered by the springs of Indian Gardens. A thousand years ago, the Anasazi people lived here and farmed what is known today as the Tonto Platform.

— Photo by Steve Rider

The footbridge over the swirling waters of the Colorado River transports hikers and mule-riders to the greenery of Phantom Ranch.

— Photo by Steve Rider 

Nearly a vertical mile below the South Rim, Phantom Ranch and its campground nestle beneath the jagged cliffs and crags.

It is impossible to sleep.

Before we had crawled into our tent, we had noticed that the rocky outcrops around us were still warm, radiating the heat absorbed from the sun during the day. On top of that, there is hardly any breeze stirring, though we had read that cool, dense air from the North Rim of the Grand Canyon often sinks down to the river in the evenings, providing respite from the day’s high temperatures.

Not tonight.

The air is still and uncomfortably hot and dry. Some campers have their tent flaps open; others are simply sprawled out on the ground in their sleeping bags or on picnic tables, but my encounter with the rattlesnake on our hike down and warnings about scorpions have made me determined not to sleep without the protection of a screened tent around me.

In addition, I am being kept awake by the dryness of the air that is sapping our bodies’ moisture and making me thirsty. The Bright Angel Campground is fairly crowded and there is the nearly constant muffled sound of voices from people as restless as we are.

Undoubtedly adding to everyone’s discomfort are the words of the Park Ranger at the evening campfire: “Now I’m going to give you the bad news. You, ladies and gentlemen, have hiked to the bottom of the Grand Canyon, one of the deepest water-cut gorges on Earth. And tomorrow morning, you are going to have to haul your butts up and out of it!”  

I had slept poorly the night before we had started our hike and the strain on our leg muscles of hiking steeply downhill coupled with dehydration requires a good night’s rest but it is obvious we are not going to get it, and sometime around 4 a.m., Steve says, “This is crazy. There is no way I am going to get any sleep. While it’s still dark let’s get moving.”

By the light of our headlamps, we load up our tent and poles in our backpacks and deliver them to the mule stable — we had discovered just before we attempted to retire for the night that for 50 bucks, the mules will haul our backpacks up to the South Rim, so we need only the light day packs we have brought and our canteens. To our surprise, the Phantom Ranch snack bar is open at that hour and we purchase a couple of trail lunches for the ascent.

As we leave the campground, the first faint light begins to glow in the east but we keep our headlamps on as we make our way over toward the river to avoid confronting snakes or scorpions. The sky brightens surprisingly fast and, by the time we reach the bridge over the Colorado River, there is sufficient light to walk without headlamps. The air now seems for the moment pleasantly cool and we are cheered by the thought that we may be able to get up and out of the Devil’s Corkscrew before the worst heat comes.

A moment to remember

Just as we start to cross the bridge, dawn’s red sunlight hits the tops of the mesas and jagged buttes and pinnacles, making them look like glowing embers and we stop to take in the spectacular scene. Just a few yards beneath us, the turbulent currents of the muddy Colorado rumble over boulders in its bed — the only sound that breaks the stillness — and the bridge vibrates with the river’s power.

There is not another living soul in sight — it is as though we are the only two people in the canyon, a moment to remember all of our lives.

The trek back along the bank of the river somehow seems less of an ordeal than it had the previous day, perhaps because we know with every step the South Rim is closer. Along with our friends Rich and Teresa, we have made reservations for that night at the venerable El Tovar Lodge, which has a swimming pool, a highly-regarded dining room, and air-conditioning.

But between Bright Angel campground and the South Rim lie 4,500 feet of elevation gain over 10.3 miles of trail and those facts provide a reality check to the elation we have felt in our view from the bridge.

We arrive at the base of the Devil’s Corkscrew and we each guzzle close to a quart of water before we begin to climb. From below, the torturous twists and turns of the trail are not very obvious and we discover to our pleasure that the steep, stony trail is in some ways easier to ascend than it was to descend for the simple reason that gravity is not forcing us forward and down at awkward angles with each step.  Also, at this early hour of the day — it is around 6 a.m. — much of the Corkscrew is in shadow, tucked as it is in its own side canyon.

We pass a few lone hikers headed down who have also taken advantage of the cool morning — they must have started their descent around 2 a.m. Oddly, except for exchanging hasty greetings, no one stops to chat — everyone hiking wants to get the Corkscrew behind them.

As we climb, we make occasional brief stops to let the muscles in our legs relax but the lure of getting back to Indian Gardens before the sun begins again to turn the Corkscrew into a furnace is irresistible.  We are also pleased to discover that, with increasing altitude, the temperature is staying steady or perhaps even dropping.

This seems to energize us and within an hour we have reached the sign describing the Great Unconformity — the Corkscrew is now history. The green cottonwoods of Indian Gardens and the cool shade they offer seem a prize for our morning’s efforts and we take a break for water and snacks.

Intricate features revealed

Descending Bright Angel Trail, we were rewarded with the vast, panoramic views of the canyon with its stunningly sculptured towers of rock. But on the ascent our backs are to the long views much of the time and the intricate features of the various layers of sandstone and limestone are revealed.

The National Park Service has set up labelled displays of the fossils: There are trilobites and their fossilized trails, brachiopods — oyster-like shellfish — snails and fragments of crinoids, commonly known as sea-lilies. Incredible to think that hundreds of millions of years ago this bone-dry environment was from time to time under a warm, shallow sea dotted with reefs and islands like today’s Bahamas.

Yet in between the limestone strata are the various strata of sandstone, and these show thin laminated layers meeting each other at odd angles: features known as cross-bedding, representing petrified deposits of sand left there by ancient shifting winds. This tells of Earth’s surface cyclically heaving upward, causing prehistoric seas to retreat and turning the landscape into desert as it is once more today.

In many places, in the precipitous, far-off limestone cliffs there are dark cave openings that in times of unusually wet weather may even today gush water. Most are unexplored as it is appallingly dangerous to get to them: Explorers must either rappel down from hundreds of feet above the entrances or do challenging rock climbs from below.

The caves are very ancient features and the few that have been entered have yielded stalactites and stalagmites which have been radiometrically dated to over 7 million years ago. But were these caves here before the Grand Canyon formed or are they more recent?  The answers are controversial and contradicting and are part of the centuries-long debate as to just how and just when the Grand Canyon came to be.

As we climb above Indian Gardens, we encounter increasing numbers of hikers, a few bound for Phantom Ranch and the campground, many for Plateau Point.

One young couple says, “We’re almost down to the river, aren’t we?” and we gently explain that they still have a long way to go. They have no idea what the Devil’s Corkscrew is and we realize then that they are not following a map.

In addition, the young man is wearing open-toed sandals and at the end of the hike is likely to have blisters on his feet the size of golf balls. But rather than trying to scare them with dire warnings, we tactfully suggest that, given their inexperience and the rising temperatures as they descend, they might want to turn around at Plateau Point — which, to be sure, is far deeper into the canyon than most visitors go.

They seem grateful for the advice and head off downward energetically. As the saying goes, “Experience is the best teacher.”

End in sight

It is now late morning and we are approaching the last switchbacks of the trail before we reach the South Rim.  We are dusty and sweaty and obviously look tired but are exhilarated to see the end of the challenge so close now.

The temperature has continued to remain steady as we climb and now stands in the low 70s — fine for hiking. This section of the trail is crowded with visitors, many with little kids, doing just as my family did those many years ago — descending a few hundred feet on the Bright Angel Trail to get a feeling for being in the canyon instead of just looking at it, as it were, from the outside.

A ranger we talk to later informs us that a survey has revealed that the average time visitors actually spend looking at the Grand Canyon is a minuscule 12 minutes before they head off to the souvenir shops, the game rooms, and swimming pools of the hotels, or one of the numerous food services.  To me, this is comparable to someone’s standing on a bluff on the New Jersey side of the Hudson River, taking a couple of quick selfies with the skyscrapers of Manhattan in the background, and texting friends that they have been to New York City.

Following directions in our trail guide, just before we reach the rim we take a look into an inconspicuous hollow above the trail and there we see pictographs left by the Anasazi or one of the other ancient peoples who have made their ways into the canyon. A handprint and figures of deer and other animals appear in red paint, surprisingly well-preserved in this dry environment even though vandals have managed to find and mar some of them.

Their presence emphasizes the long history of the trail and evokes admiration for people with primitive equipment who must have been motivated by the same sense of awe and wonder that lures hikers today.

As we arrive at the rim, several people come over to ask if we have come up from the bottom and seem impressed when we answer in the affirmative. One elderly man says, “It must be a great experience,” and sounds wistful.

“Yes, yes it is,” is our response.  “It really is.”

Not particularly eloquent, of course — but sometimes simple words convey the most truth.

In any case, no question we hear matches what a park ranger tells us he was asked upon emerging from one of his many trips into and out of the canyon. A middle-aged couple approached him — dusty and sweating and sunburned like ourselves — and asked if he had been to the bottom, and when he replied that he had, the woman asked, “Is there anything down there?”

As the saying goes: If you have to ask a question like that, you would never understand the answer.

We head for our hotel, a hot shower, a good dinner with a celebratory glass of wine, and a well-deserved night in a real bed. And, as was true of so many before us who have descended into the depths of the Grand Canyon, we dream.

Location:

— Photo by Steve Rider

Mike Nardacci stands at the trailhead for Bright Angel Trail. In the center of the photo and 3,000 feet lower with its spectacular view of the Inner Canyon is Plateau Point, the goal of many day hikers.

— Photo by Steve Rider

At the beginning of the Devil’s Corkscrew, a sign stands next to the otherwise unobtrusive Great Unconformity. At right, the precipitous cliffs of the Vishnu Schist plunge nearly a quarter of a mile, forming the Inner Canyon.

— Photo by Steve Rider

The torturous switchbacks of the Devil’s Corkscrew: During much of the day, there is no shade in the Corkscrew, making passage through it a challenge.

— Photo by Mike Nardacci

The turbulent Colorado River is met by the Bright Angel Trail. Spanish explorers named the river for the faded-brick color of silt and sand it carries. In the background rise mesas and buttes of the Upper Canyon.

Everyone remembers the first time they see the Grand Canyon.

Mine came over half a century ago when I was 14 and it is still burned into my memory along with my first sight of the Giza pyramids; my first close-up look at an erupting volcano; and my first view — from a hillside fragrant with pine resin called The Pnyx — of the Parthenon at night glowing in subdued flood lamps above the noisy, twinkling streets of Athens like a vision from myth.

My family was on a cross-country trip and we had driven up from Phoenix, Arizona that day. The first half of the drive had been blisteringly hot.

Cars did not have air-conditioning in those days and my mother and father had shared the driving, but even today it is a tiring trip, passing first through forests of giant saguaro cactuses, then ascending through cool mountain meadows where elk wander and, skirting Flagstaff, heading into high desert where the apparently endless flat terrain gives no hint of the awe-inducing landscape that lies just to the north.

We arrived around 10 at night at the venerable Bright Angel Lodge where my parents had reserved a cabin that was close to the South Rim of the canyon. They were both looking forward to getting a shower and a good night’s sleep but I remember being appalled that they did not first want to see the canyon.  Assured by the hotel clerk that there was a safe viewing deck right behind the main lodge, I took off on my own, promising to join the family at our cabin in 15 minutes.

The clerk directed me to a doorway that led out onto the deck and it took a few moments for my eyes to get accustomed to the darkness. The bright first-quarter moon had risen in the eastern sky and slowly there emerged from the dark vastness the silhouettes of great craggy pinnacles and towers and though in the dark it was impossible to gauge size or distance, I could tell what lay before me were massive structures stretching to the horizon.

Far, far below was what appeared to be a thin, meandering line drawn in softly luminous ink — my first glimpse of the far-away Colorado River. A mild breeze was rising from the depths, carrying with it the fragrance of sage and other desert plants, an odor I have heard described as “desert incense.”

An eerie howl was the only sound that broke the overwhelming stillness — perhaps somebody’s dog, though at 14 I was sure I was hearing a coyote. However — I have since spent enough time in the Southwest to realize that it probably was a coyote as these critters are ubiquitous in the deserts.

At any rate, with that unearthly sound, I suddenly became aware that a dark, precipitous abyss lay before me and for a moment I steadied myself against the retaining wall that surrounded the deck as I was overcome with the vertiginous sensation that I was about to be pulled over the side. I remember withdrawing into the light of the lobby of the lodge where everything was on a more human scale and running to our cabin.

The next morning, my father took my sister and me on a short hike down the iconic Bright Angel Trail that leads down to the Colorado River. We were on a tight schedule and had to meet relatives in Los Angeles in two days but Dad wanted us to have the experience of being down in the canyon instead of just seeing it from the top.

My mother declined and opted for a walk on one of the paths that run along the canyon rim, meandering through desert plants and offering dizzying views of the spectacularly colorful rock formations below.

My recollection is that we walked not more than a half-mile down the steep, dusty trail and foolishly had not brought any water. The South Rim is at 7,000 feet and tends to be fairly cool even in summer, but one of the great misconceptions novice hikers entertain — and we were definitely novices! — is that temperatures down in the Canyon are cooler than at the rim. (Fact: Temperatures tend to decrease with increasing elevation, and increase with decreasing elevation, a lesson I certainly knew many years later but did not appreciate until I hiked with a friend all the way to the bottom.)

I had been a rock collector since I was around 5 years of age but at 14 I knew very little about geology though I had read in a guidebook that the canyon had been cut by the Colorado River over millions of years. I was fascinated by the fact that the rocks were in layers of many different colors even if I had no idea why — Dad probably tried to explain that to me, but who remembers lessons from when you are 14?

We probably descended 500 feet or so below the canyon rim — following, as it turns out, a route first used by the ancestral pueblo people long known to history as the Anasazi. Beautiful as the scenery was, I remember being surrounded by the massive stone forms and experiencing again the feeling of vertigo as we gazed off into the immense gulfs of the canyon.

It was with some relief that my father told us that we had to head back up to meet Mom and take a drive along the rim to see more of the awesome scenery before we left on the next leg of our drive west. In all, we spent less than 24 hours at the canyon — fairly typical for the average tourist even today.

But that brief descent of the Bright Angel Trail remained lodged in my memory as one of the highlights — albeit a bit scary — of our California trip. And the sight of the far-away bottom of the canyon and that narrow-seeming Colorado River surely fired my determination to come back someday and hike all the way down.

Return to the canyon

It was many years later that I returned to the Grand Canyon (rather more than fully grown!) but this time with several friends: a fellow hiker named Steve with whom I planned to hike to the bottom and tent overnight in the Bright Angel Campground near legendary Phantom Ranch, and an old high school buddy named Rich and his wife who were going to do the mule ride down to the bottom and stay in one of the rustic (but air-conditioned) cabins at the Ranch.

We arrived on a deceptively cool August evening after a long drive from New Mexico and spent the night before our trek in the park campground. This turned out to be a mistake, because the rule most campgrounds state about “quiet hours” after 10 p.m. are routinely ignored, and I remember spending an uncomfortable night trying to sleep while boomboxes near and far broke the stillness with rock, rap, and mariachi music.

I recall waking from what little sleep I had gotten with a sore back and thinking how nice it would be to find a quiet hotel room somewhere and sleep for a dozen or so hours instead of embarking on what might be the most epic hike I had ever made.

But around 8 a.m., backpacks on, we parted from our friends, planning to join them at Phantom Ranch at the bottom and began our descent of the Bright Angel Trail, one of several maintained trails that descend into the canyon. It follows a prehistoric fault line that slices through the rock layers and which subsequently became a channel for flowing water — rare in these times — which eroded a pathway affording the ancient Anasazi people and modern hikers access to the bottom of the Canyon.

Layers reveal history

The layers of rock into which the Grand Canyon has been incised by the Colorado River can be thought of as a stack of books revealing segments of Earth’s history, with the most recent events in the “book” on top. From a distance, the strata (layers) may look thin, but hiking down through them makes one realize their immense breadth. Individual strata may be hundreds of feet thick, each one representing a dramatic change in the environment in which it formed.

Three of the broader layers are limestone, known in order of age from youngest to oldest as the Kaibab (Permian Period), the Redwall (Mississippian Period), and the Muav (Cambrian Period), making them between 250 and 530 million years old. These layers formed in warm, shallow seas and contain characteristic fossils such as trilobites and crinoids — also called “sea lilies,” but which in spite of their flower-like appearance are actually animals.

Yet they are interspersed with layers of sandstone called the Coconino, the Esplanade, and the Tapeats and major shale layers known as the Hermit and Bright Angel. The sandstone formed at times when the ancient seas receded and this part of the Southwest, like today, was desert characterized by vast fields of windswept dunes. Some of the outcrops exhibit the ancient tracks of lizards and other reptiles that scampered over the dunes.

But the shale layers formed when the area was under very deep waters and is often dark, indicating an environment that was oxygen-poor and mostly hostile to life, showing occasional worm tubes but few other signs of living creatures.

At the very bottom of the Canyon at the level of the Colorado River is a near-quarter-mile thick layer consisting of the Vishnu Schist, which is metamorphic, infused with fingers of the igneous Zoroaster Granite. These rocks are well over 2 billion years old and are indicative of a whole different range of formation processes: a veritable library of the region’s changing geologic history.

The strata weather and erode in different ways and at different rates, and this fact is responsible for the stunning sculptured appearance of the canyon’s landscape. Very hard rocks — such as the limestone, sandstone, and schist — tend to weather into huge vertical slabs that spall off in massive vertical slabs producing steep, precipitous slopes with enormous angular boulders at their bases.

Shale layers, on the other hand, are far less resistant to agents of weathering and erosion and result in gentler slopes, often littered with small pebbles and gravel. These processes can be observed in our own Thacher Park where the limestone rock layers of the Indian Ladder Trail have formed steep cliffs, but the long, gentler talus slopes beneath them are composed of dark shale and brittle sandstone layers, stretching down from the Helderberg plateau toward Altamont and New Salem.

At the canyon, the thickness of the strata and the varying steepness of the slopes result in the frequently scary exposure but always spectacular views offered by the various trails that descend to the Colorado River. It is not unusual to be hiking on a trail that is less than five feet wide with a sheer drop of several hundred feet off one side, and it takes us a couple of hours of hiking before we even begin to get used to the exposure, made worse by the fact that, when a mule train passes, hikers are required to stand on the outside until the last mule has gone by.

Believe me, it is a memorable experience to be perched on the edge of a cliff with a 500-foot, almost-vertical drop behind you while an odoriferous mule carrying a terrified-looking passenger lumbers by you with only inches to spare.

Indian Gardens

After about three hours, we arrived at the area known as Indian Gardens, a popular resting and watering place for hikers. Often thought of as the halfway point on the descent, it is actually about two-thirds of the way down from the South Rim in terms of elevation loss.

It is located at the interface between two important rock layers — the Muav Limestone and below it the Bright Angel Shale — part of what is known as the Tonto Group (no relation to the Lone Ranger’s companion). Here the Bright Angel Shale has weathered out into a broad plateau known as the Tonto Platform and offers respite (briefly!) from the steepness of the trail.

The Muav Limestone is somewhat permeable and can function as an aquifer, allowing the development of caves and small conduits carrying water. But the Bright Angel Shale is an aquiclude, meaning that water cannot pass through it and so the contact between the two layers features numerous springs, some with potable water.

Long ago, the ancient Anasazi people had descended the trail through the Bright Angel fault and built a series of small pueblos and kivas — underground religious structures — from the endless supply of rocks spilled down from higher up and farmed the Tonto Platform — hence the name “Indian Gardens.”

Dusty and dilapidated, the ruins of the pueblos are still visible and leave one to wonder about the mysterious people who passed their lives in this hauntingly isolated spot.

It is a gorgeous place, featuring some shade-offering cottonwood trees, and it is surrounded by towering buttes and pinnacles of varicolored rock. Their tones change from moment to moment with the movement of the sun and they cast deep, mysterious-looking shadows across the rocky wilderness.

The platform itself consists of gently rolling hills incised by steep valleys that in wet weather transport water to the Colorado River. The relative moistness of the plateau has allowed an array of desert plants to flourish there, such as cactuses and wild sage.

It was while I was following a small side trail that leads to a spring where I planned to fill my canteens that I encountered one of the canyon’s more interesting wild residents. I came upon what appeared to be a yard-long strip of pinkish leather draped over a scraggly-looking shrub and the absurd thought briefly passed through my mind that someone has lost a belt.

All at once, its nether end went vertical and an electric-sounding buzzing broke the stillness of the canyon. I froze in my tracks and realized it was a specimen of the Grand Canyon Rattler that lives nowhere else.

We regarded each other suspiciously for a few moments and then, staying well out of its private space, I made a wide arc and continue on my way, carefully watching it as I went. After a long moment, the buzzing stopped and its tail dropped. It had vanished when I returned with my full canteen so the encounter ended well for both of us, but, suitably alerted, I watched every step I took before I returned to the main trail.

As we were enjoying the leafy shade and a long cool drink of water along with some salty snacks — it’s important to maintain one’s electrolyte balance when hiking in heat — a line of mules and riders approached. The mule team leader known as the Wrangler urged all of the riders to drink plenty of water and a couple of them showing signs of overheating were hosed down with cold water from a spring.

We chatted briefly with our friends, Rich and Teresa, whose clothes were covered with dust and who admitted to looking forward to their air-conditioned cabin and a cool shower. They reported a few anxious moments on their ride as the mules apparently love to walk right on the outside edge of the trail where one misstep would send both mule and rider tumbling into the abyss. We planned to meet that evening in Phantom Ranch’s canteen for dinner.

Great Unconformity

Leaving Indian Gardens, hikers get a bit of a shock for they are soon at the top of The Devil’s Corkscrew, a dizzying series of very tight switchbacks that descend over 1,300 feet in approximately 3.5 miles. The Corkscrew offered virtually no shade and the temperature was rising steeply.

The sense of exposure is extreme and with every step hikers become aware of the fact that they are being engulfed by the lower depths of the canyon. One advances with a mixture of awe and trepidation with each dusty step.

As the trail begins its descent, a National Park sign alerts hikers to the fact that they are now passing through what geologists call the Great Unconformity. In simple terms, a geologic unconformity is the boundary between two rock or sediment layers that differ widely in age and often in composition.

A simple example can be found outside the door of anyone living on the Helderberg Plateau or in the towns that snuggle at its base. The surface sediments here are Pleistoscene — rocks and soil left behind 10,000 or so years ago when the glaciers retreated. But the sediments sit upon rock strata that come from the Devonian Period — 400 million years ago — or even earlier. That time gap between them represents an unconformity of hundreds of millions of years.

The Great Unconformity is in no way attention-grabbing, and without the sign no one lacking an extensive knowledge of geology would be likely to take a second look at it. Layered 550-million-year-old Tapeats Sandstone rests tightly on the quarter-mile-thick Vishnu Schist — a metamorphic rock — containing intrusions of the igneous rock granite.

The schist represents very ancient shale layers pressed and folded and cooked in a mountain-forming episode called an orogeny. It is all that remains of what was once a range of near-Himalayan heights that rose around 2 billion years ago — close to half of the age of the Earth — and was then ground down steadily over hundreds of millions of years by the agents of erosion.

In other words — in a space too thin to place one’s fingers in, something close to 1.8 billion years of Earth’s history has been wiped away. We know this because, in many other places in the United States and in the world, rocks of the intervening eons have been discovered.

The Great Unconformity can be seen in other parts of the Southwest, but nowhere is it visible in a setting more dramatic than this. And given the hardness of this inner canyon rock, the Devil’s Corkscrew features drop-offs between its tight switchbacks that are vertigo-inducing and we found ourselves grateful that we were not on mule-back.

Reaching the river

It was now near noon, and as the sun had ascended into the cloudless Arizona sky, its light being concentrated in the confines of this canyon-within-the-canyon, the temperature soared. Descending the meanders of the Corkscrew is numbing: left turn, right turn, left turn, right turn again down a rock-strewn trail, kicking up dust with every step and trying hard to avoid deposits of mule-poop.

The gradient was so steep we had to force ourselves to hold back from a trot — unthinkable in this heat and with such unstable footing. In the stark sunlight, the varying colors of the rock layers seemed to be bleaching to dull shades of tan and everywhere there were dusty cactuses of several kinds, constant reminders that we are in the desert — as if we needed such reminders.

In less than an hour, we reached the banks of the Colorado River, and what appeared from the South Rim to be a narrow, lazily-moving muddy stream was revealed as a roaring flood, its waters faded brick-red from the rust-colored sediments it carries.

Perched on the bank was a small shady shelter where hikers could fill their canteens with fresh water and there is usually a park ranger to offer aid and answer questions. Everyone entering the cool interior remarked on the oppressive dry heat and to our astonishment the ranger told the assembled group, “You folks are lucky — it’s only 107 today.  Yesterday at this time it was 123!”

Whatever good news that represented, the fact is that we were still 2.3 miles from the Bright Angel campground near Phantom Ranch. Before we started our trek, we had cut down what we were going to carry to the absolute minimum equipment we would need for a single-night stay — about 15 pounds each.  Descending the trail in the cooler morning, the packs had not seemed so much of a burden.

But as we commenced our hike along the river toward the campground they seemed to gain weight with each step and there was absolutely no shade. Moreover, the rock-littered, dusty trail along the river is not flat — it goes up over and down a series of hills and gulches formed from massive piles of talus that have spalled off from the higher elevations.

In the wilting heat and with the droning of the river’s rapids, the hike is punishing. The spectacular scenery rising above us offered little consolation for the ordeal and we realized that no matter how much water we guzzled from our canteens on the way down, it was not enough: We were feeling the effects of dehydration.

On to camp

After what seemed like hours — but was really only about one — we spotted the sturdy metal bridge across the Colorado that leads to Bright Angel Campground and we gratefully crossed it, only a few yards above the roiling waters of the Colorado River.

On the far side near some cottonwood trees are the remains of still another Anasazi pueblo and a kiva close to where the Bright Angel Creek spills down from the North Rim of the Canyon to join the Colorado — another green place in the desiccated wilderness of the canyon.

Beyond them is the campground, and after checking in we hit the snack bar and guzzled what must have been two quarts of cold lemonade each. We then proceeded to put on our bathing suits and go to join other exhausted hikers sitting in the creek and letting the cold stream spilling down from the North Rim of the canyon refresh us.

Later in the afternoon, Rich and Teresa arrived and showed us their cabin. It is Spartan — but its air-conditioner works; it has water for hot showers; and. though the beds look like they came from a college dormitory, we are assured that they are clean and comfortable.

We assemble at dinner time in the Phantom Ranch canteen. Meals are served family-style at long tables — like at a church supper.  Steve and I have pre-ordered beef stew with chocolate cake for dessert, and perhaps it is the effect of our day’s ordeal or perhaps it is the spectacular setting but the humble stew tastes like the specialty of a five-star restaurant and the cake seems the equivalent of some gourmet French pastry.

In any case, we wash it all down with glass after glass of cold lemonade and, after dinner, Rich and Teresa head off to their air-conditioned cabin for a good night’s rest in a real bed. At dawn the next day, they will again mount up on their mules and head back up to the South Rim.

They will be following the South Kaibab Trail, which most guidebooks tell hikers ascending the canyon to avoid as it has almost no shade and is even steeper than the Bright Anger Trail. Steve and I head over to a small amphitheater located near the river for the evening ranger presentation.  

The temperature is still in the nineties, but what is a ranger presentation without a bonfire? So the woman ranger who is conducting the presentation has built a small fire that crackles and spits agreeably, but in this dry heat not one of the two dozen or so hikers gathered for her talk wants to be near it.

Before she starts, we have time to contemplate the setting: We are seated on primitive benches situated on some of the oldest rock on Earth’s surface, surrounded by towering mesas, buttes, and pinnacles slowly sinking into purple shadows in the approaching twilight. Far above us and several miles away, tiny lights from the hotels scattered along the South Rim glitter dimly like mirages and above them in the clear violet sky the planet Venus gleams.

The ranger takes the podium and says to the gathered crowd: “Congratulations everybody! You have hiked to the bottom of the Grand Canyon, something very few people ever have the opportunity or the stamina to do!”

She points out the towering structures of stone and explains the origin of some of their names: Zoroaster Temple, Cheops Pyramid, Shiva Temple, Vulcan’s Throne, Isis Temple — names to conjure by if we were not all too tired to conjure. She talks about the geology of the rock strata and their mind-numbing age and explains how the flowing waters of the Colorado River and the thousands of small side canyons have carved this great abyss over millions of years. The crowd is silent — partly out of exhaustion but mostly in awe of her presentation

Then all at once she says, “Now I’m going to give you the bad news. You, ladies and gentlemen, have hiked to the bottom of the Grand Canyon, one of the deepest water-cut gorges on Earth. And tomorrow morning, you are going to have to haul your butts up and out of it!”

The poetry of the moment disappears, and all at once it hits us: Today we hiked down into this spectacular place in the oppressive heat. Tomorrow we have to do it in reverse — and the Devil’s Corkscrew looms in our imaginations like the challenge of a lifetime.

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