Out in America's Never Never: A Tale of Two Towers (and a few more)

Agathla Peak north of Kayenta, Arizona

America's Never Never is full of strange and wonderful sights. We had left the forested Black Mesa and its rather depressing strip mines and headed east to the village of Kayenta on the Navajo Reservation, then turned north towards Utah. We had dropped several thousand feet and were traveling through a more barren landscape (the barrenness exacerbated by the ongoing drought).

Now, before I go much farther, I need to talk about childhood cartoons. I surely date myself severely when I note that my favorites were the Looney Tunes, especially Bugs Bunny, but there was a special place in my heart for Wile E. Coyote and that nefarious arrogant Roadrunner.  I had been to places like Joshua Tree National Park and the Mojave Desert, so I knew that no desert really looked at all like those cliffs and spires that Wile E. was always falling off of.

At least not until I reached the Navajo Country around Kayenta and Monument Valley. Suddenly I was standing not only in a Roadrunner cartoon, but John Wayne would be riding up any moment in a stagecoach. There really were towering spires in the desert!

I was pretty lucky in that my parents were the ones who originally introduced me to this country on our family vacations. I learned about these deserts in my childhood, but I was left with a lot of questions not readily answered. It wasn't until I became a geologist that I fully appreciated the processes and history that produced these incredible landscapes. And I've been bringing my students here ever since to show them that deserts aren't just cacti and sand dunes.

Agathla Peak just north of Kayenta

There are different kinds of "towers" in Navajo country produced by quite different processes. There is a great spot on Highway 163 about ten miles north of Kayenta to compare the two. To the east is Agathla Peak (or "El Capitan") standing some 1,300 feet over the highway (above). To the west stands Owl Rock (below).

Agathla is one of the more spectacular examples in the Navajo country of a volcanic neck or diatreme, the core of a deeply eroded volcano. Although the towering spire appears dark it is mostly composed of large chunks of sandstone that collapsed into the interior of the volcano after a violent explosive eruption. One can see dark dikes of basaltic-looking volcanic material; the rock is called minette, which is a relatively rare potassium-rich volcanic rock. The network of dikes protected the core of the volcano while the remainder was eroded away. The intrusion is just one of dozens covering an area of around 20,000 square kilometers around Four Corners called the Navajo Volcanic Field. Shiprock is perhaps the most familiar of these features.

Owl Rock, the tower on the other side of the highway,  is quite different. It is clearly layered, and the layers are horizontal. It is an erosional outlier of the same sequence of sandstone, siltstone and shale that can be found in many of the cliffs throughout the region. Sedimentary rocks are not known for producing towers and spires under "normal" conditions (read "characteristically humid conditions where most people live"). In the dry desert environment of the Colorado Plateau, resistant rocks such as lava flows or in this case quartz sandstone will form a protective cap that generally prevents the otherwise rapid erosion of the softer underlying sediments.

The tower is composed of Triassic and Jurassic-aged rocks of the Kayenta and Navajo Sandstone formations. Beneath the tower are the siltstone and clays of the Triassic Chinle Formation (or Group). The Chinle was laid down in floodplains and lakes in the earliest years of the dinosaurs. Distant volcanic eruptions (some near my own Sierra Nevada) laid down ash deposits that have oxidized into colorful red, brown, yellow, and lavender clay-rich strata. Some of the ash layers are famous for their petrified logs, most notably at Petrified Forest National Park in Arizona. We have seen logs in the vicinity of Agathla Peak and Owl Rock as well.

But what about the cliffs? How did they form?

The Navajo Sandstone is a solid rock but when it is stressed by regional deformation it tends to develop vertical fractures called joints. The Navajo may prevent the rapid erosion of the underlying shale layers, but the rocks do eventually get eaten away, undercutting the sandstone. The rock falls away along the joints in a process called cliff retreat. In this way a plateau shrinks to become a mesa, a mesa becomes a butte, and eventually only a spire remains.

It turns out that Owl Rock is simply a foreshadowing of the incredible sights ahead. As we passed into Utah we reached Monument Valley, a place where cliff retreat has produced a spectacular array of mesas, buttes and spires. The formations are different because we have crossed onto a deformed section of crust called the Monument Upwarp. We have reached rocks that are late Paleozoic in age (Permian), between around 250-300 million years.

At Monument Valley, the vertical sandstone cliffs are composed of the DeChelly Sandstone. A thin layer called the Shinarump Member of the Chinle Formation forms the top layer of many of the spires and buttes. The gentler slopes below the cliffs are the finer sediments of the Organ Rock Shale. The Permian Period was a time of reptiles, but not dinosaurs. The terrestrial environments were dominated by a group called the Therapsids, or "Mammal-like" Reptiles. These animals had a more vertical stance that distinguished them from the sprawling gait of other reptiles, and a number of other features that are mammalian in nature, including differentiated teeth. They gave rise to the mammals in Triassic time. The region has yielded up a number of specimens.

Monument Valley is a tribal park administered by the Navajo people. Many people (who don't know who John Wayne was) will know the place as the spot where Forrest Gump decided to stop running across America ("What are we supposed to do now?").

We had a lecture at the overlook and headed up the highway to a sight that was an absolute first for me, the Valley of the Gods. More on that in the next post!

Vagabonding Across the 39th Parallel: Sun and Rock in Arches National Park

Last summer we set out on a vagabonding journey that roughly followed the 39th Parallel across the western states of Nevada, Utah and Colorado. By vagabonding, I refer to the set of loose rules we followed to not plan more than a day or two in advance, and try to see as many new sights as we could see. We ultimately made it to Rocky Mountain National Park, and now after 10 days on the road, we were headed west, slowly returning home to California.  Our winding road brought us to the town of Moab, Utah, and Arches National Park. We were now on the Colorado Plateau, a vast area of the earth's crust that was stable for hundreds of millions of years, but in recent geologic time has been uplifted and deeply eroded by the Colorado River and her tributaries.

I've been to Arches National Park a great many times, but almost always with a large group of students. A group necessitates some serious planning, and our trips usually include the same three places: a hike to Delicate Arch for the sunset, a hike to Double Arch, and a hike to Landscape Arch, the largest in the park (and probably in the world). On this particular day, our new experience was stopping and sitting at one of the less iconic viewpoints. Literally sitting, for a rather long time. We had a picnic dinner, and just experienced the desert while the sun set behind us. 

Before settling in, we made a quick circuit past the La Sal Mountains overlook and the Windows Section. The La Sal Mountains are outside of Arches National Park, but provide a spectacular backdrop to arches and fins that make up most of the scenery in the park. The mountains have an unusual origin. They are not quite volcanic in origin (although volcanoes almost surely existed here, but have been eroded away), but instead are formed of intrusive rock that reached shallow depths in the crust, wedging and bulging up the sedimentary layers that lay above the molten rock. The intrusions are called laccoliths. The mountains rise to 12,000 feet, and are often snow-covered, even in early summer.

The Windows Section contains several large arches, including Double Arch, made famous by the opening scenes of Indiana Jones and the Last Crusade. There is no deep cave up in the alcove, and no Coronado's Cross, though. Just a spectacular double arch. It's big; click on the photo below and look for the people walking under the arch.

The Windows Section is a good place to learn the stratigraphy of Arches National Park (see the picture below). There are three important sedimentary layers that are fundamental to the scenery, all Jurassic in age. The Navajo Sandstone is the preserved remains of a vast dune sea (an erg) that developed along the western edge of the supercontinent Pangea. It makes up much of the spectacular scenery at other parks like Zion and Capitol Reef, but is less visible in Arches. It makes up the lighter-colored layer at the base of the slope in the picture below.

The layers atop the Navajo Sandstone are two members of the Entrada Sandstone: the Dewey Bridge member and the Slickrock member. The Dewey Bridge formed in a tidal flat environment and has variable layers of siltstone and sandstone. It is easily eroded, which allows it to undercut the harder Slickrock member, causing the cliffs and fins in which the arches are developed. It often has a wavy "crinkled" aspect that has led some geologists to speculate that the layer was affected by the nearby impact of an asteroid at Upheaval Dome. The speculation is controversial, but the explanation appeals to me simply on the scale of grandeur and in thinking outside the box.

The cliffs at Arches are made of the Slickrock member of the Entrada Sandstone. The formation preserves sand dunes that developed along the coast of Pangea (much like the Navajo Sandstone). The arches form most often in the Slickrock member. I wrote about the formation of the arches in my series Time Beyond Imagining. Here is a short excerpt:

"The origin of the park's famous arches (there are hundreds) is tied to the salts of the Paradox Basin. The salt beds are thousands of feet thick, and when placed under pressure, can slowly flow upwards through the overlying rock, forming domes and anticlines (upward pointing folds). Over millions of years, erosion removed thousands of feet of overlying sediment, and the salt was close enough to the surface to be affected by groundwater: it was dissolved away. The tops of the folds collapsed inwards, and the Entrada Sandstone was fractured (jointing) into a series of parallel fins. A large northwest trending anticline crosses the park; most of the arches occur along the flanks of the anticline.

The top of the fins are exposed to the arid desert climate, where the rock dries quickly following the infrequent storms. At the base of the fins, where the rock is buried by soil and loose sand, the rock may stay moist much longer. This leads to the solution of the cement holding the sandstone together, and the fins start to weather from below. Eventually a small window may open up, and falling slabs of rock enlarge the opening."

The sun was sinking lower towards the horizon. We sat in the silence and ate our sandwiches; a few cars stopped briefly and people stepped out to see what we were looking at, but they were mostly in a hurry to be someplace else.

Arches is an elemental place, as most desert landscapes are. There is sunlight, and there is rock. Everything else is secondary, the plants, the animals, the people. If you are caught in the open on a hot summer day, the elements are perilous. Survival is a crapshoot. In our insulated existence, the crapshoot becomes a source of great beauty, especially as the sun sinks and the searing heat dissipates. The rocks glow, and then slowly fade to darkness.

Our minds see meaning in the random shapes of the rocks, and we make stories of their origin. Some stories involve myths and heroes, while others involve jointing and frost wedging. I enjoy both kinds. What do you see here?

The fire in the sky died away, and stars emerged in the darkness. We gathered our things and drove back into town.

Out in America's Never Never: Erg-onomics of a Desert Park

That's right, geologists can't help themselves. They like puns. This isn't a discussion of how to sit properly in a national park, or to hike without causing carpal tunnel syndrome in your toes. It's about sand, lots and lots of sand. Enough sand to cover as much as 625,000 square kilometers (about 240,000 square miles). My home state of California totals a little over 420,000 square kilometers, to give a bit of a comparison. Large "seas" of sand dunes are called ergs.

On our second day out in America's Never Never, we had reached Zion National Park in southern Utah. The park is justly famous for the sheer cliffs that tower over the valley floor, and for the beautiful scenery along the Virgin River. The scenery exists primarily because of one formation: the Jurassic aged Navajo Sandstone. The bold cliffs which sometimes have sheer drops of 2,000 feet (600 meters) are composed of cemented dune sands of an erg that once extended from southeastern California to Wyoming and Idaho. There are few if any places like it in the world today.

This vast amount of sand had to come from somewhere. Recent studies have demonstrated that it was probably eroded from the Appalachian Mountains and transported by rivers to the Midwest. The evidence is mineralogical, but it also makes sense because the eastern mountains were the only range in Jurassic time with enough elevation and extent to account for the approximately 60,000 to 140,000 cubic kilometers of sand (14,000-34,000 cubic miles). Some material may have come from the rising Sierra Nevada magmatic arc, but that range was small in comparison.

The Navajo Sandstone ranges in color from pure white to dark reddish-brown. Iron oxide minerals provide the color. Their presence may be related to petroleum that may have once existed in the unit (if it did, it would have been a resource to dwarf Saudi Arabia).

Zion National Park is just one of the spectacular exposures of the Navajo Sandstone to be found in the Colorado Plateau region (our stop in Valley of Fire also was in the same unit). It is in Zion that the greatest thickness of the unit is achieved, and the scenery is truly grand. A visit to the park should always include an exploration of the Narrows of the Virgin River, and if one is in good shape, a visit to Angels Landing or Observation Point is a great idea. If one is straining one's neck by looking up at the cliffs, a drive to Lava Point is in order. From the end of the gravel road, one can look down into the canyons from above.

Photo by Mrs. Geotripper

If you are having trouble imagining the sand dunes themselves, hop on over to nearby Coral Pink Sand Dunes State Park to the east of Zion National Park. We did, and had a great time looking at (and playing in) recycled Navajo Sandstone. The park has examples of several types of dunes, and has areas of active dune formation and migration as well as dunes that have been anchored by vegetation.

Photo by Mrs. Geotripper

Coral Pink Sand Dunes are far too limited in extent to be considered an erg (in the United States, only the Algodones Dunes of Southern California are considered to be of sufficient extent at 800 square kilometers). It is fascinating to think that the sand of which the dunes are composed once was carried in a Mississippian-sized river from a vast mountain range in the eastern United States, formed dunes in one of the largest sand seas ever to exist on the planet, was locked in solid rock for 200 million years, and only a few thousand years ago was released to bounce in the wind once again.

Photo by Mrs. Geotripper

Tse' bighanilini and Hasdestwazi, "the place where water runs through rocks", and "spiral rock arches."

Glen Canyon was a beautiful, magical place that was unceremoniously flooded under the waters of Lake Powell (and I'm pretty sure John Wesley Powell would have been appalled that his name was given to the lake). Despite the gigantic eyesore of Glen Canyon Dam, there are some incredible places to explore in the immediate vicinity. One of them is Antelope Canyon, one of the Tribal Parks managed by the Navajo Nation. The two parts, upper and lower, of the canyon are called Tse' bighanilini, which means "the place where water runs through rocks", and Hasdestwazi, or "spiral rock arches."

Natural arch within Lower Antelope Canyon

Each of the canyons is worth a look. The upper canyon is justly famous for the noon hour beams of sunlight piercing the near total darkness of the deepest passages. It is also level from one end to the other. But it also requires a ride from town that includes an unbelievable race up a pure stretch of loose dune sand. And it is crowded, especially during the aforementioned noon hours when you might find yourself standing shoulder to shoulder with hundreds of other people. It's not a place for the claustrophobic.

On our recent tour, we opted for the lower canyon. It doesn't have the piercing beams of sunlight, and it is not level, requiring steps and ladders for access. But you don't have to be ferried up Mr. Toad's Wild Ride, and it tends to be far less crowded (in my three trips, anyway).

The tours of these incredibly beautiful works of nature begin beneath the shadow of the monstrous coal burning power plant just outside of Page. The coal mines are sixty miles away, but the energy infrastructure is here near Glen Canyon Dam. We were given a short safety lecture before walking down the end of the lower canyon.

It's hard to believe that such a treasure lies hidden in these folds of crossbedded Navajo Sandstone. The canyon is more than a hundred feet deep in most places, but only a few feet wide at the top. The guide politely asked us not to jump across the top of the canyon, prompting me to wonder what story was behind that rule...

Antelope Canyon drains an area of dozens of square miles, but the rushing waters of the occasional flash floods are forced to cross two ridges of Navajo Sandstone. The rock is cemented well enough to form vertical cliffs, but at the same time the sandstone is easily and quickly eroded by fast-moving sediment rich water. The result is an incredible labyrinth of looping and curving channels.

The natural curves of the canyon are accentuated by the crossbedding of the Navajo Sandstone. The Navajo formed as a gigantic sand dune sea that extended from Wyoming and Colorado to Nevada and eastern California. The crossbeds are the preserved slipfaces of the sand dunes. The dunes were present during the Jurassic Period, when dinosaurs wandered across what is now the southwest United States.

The narrow canyon can be dangerous. Storms that are dumping floodwaters upstream might not be visible from the parking lots. After a horrific tragedy in 1997 that caused the deaths of eleven people, rescue measures have been put into place, and tours aren't offered when rain threatens the headwaters region.

The canyon is full of abstract shapes and forms, and a photographer could wander for hours through the passageways (two hours to be exact, for an extra fee). Photography is allowed and encouraged by the guides, and they offer advice on shutter speeds and the like. It's been said that one can't take a bad picture here, but believe me, it's more than possible! The sharp contrast between light and dark wreaks havoc with photo framing. It challenging, but wonderful fun as well.

My favorite pictures occur where the sunlight is indirect and reflecting from above. The resulting yellow and golden hues are beautiful; the rocks seem to glow with inner light.

The texture and light are unique. If you are ever in Page, don't be afraid to put out the tour cost (between $20-35, with a $20 premium for those noontime tours in the upper canyon).

As is usual with my visits to the canyon, I have more pictures then I have words. Enjoy!

For the second time in my three tours through the lower canyon, our guide offered some beautiful flute music in the deepest part of the canyon. Here's the video:

Then it was time to go. We climbed up the last ladder into the blinding sunlight.

Volcanoes, Lava Flows, Fault Zones: What Park is This? You Might Be Surprised...

...unless you've been following my latest blog entries, anyway. The beautiful exposures of the crossbedding in the Navajo Sandstone (above) provides another clue; we are in Zion National Park, but in a section that is ignored by probably 95% of the park's visitors. As far as I'm concerned, it can stay that way in perpetuity, because it is one of the more beautiful spots on the Colorado Plateau, and I'm not too keen on seeing it crowded and busy. But I'll share it anyway, because anyone who takes the trouble to get out to Zion and wants to escape the crowds for awhile deserves to know of this place.

It's called the Kolob Terrace Road, and it takes one from the lowest elevations of the park to the highest, and from the end of the road at Lava Point Overlook, you get to look down into Zion Canyon. It is also the most geologically interesting part of the park, providing a look at the entire stratigraphy of the park, recent volcanic activity, and potentially active fault zones. For the biologist, it provides a range of biomes, from the desert to near alpine conditions. On a hot summer day, the high country is cool and green. There is even a small campground if you want to linger. Trailheads along the road provide access to "The Subway" and Kolob Arch, perhaps the second largest natural arch in the world.

The road starts in the village of Virgin and almost immediately does something unusual and spectacular. It climbs right up the middle of an inverted stream, a place where a lava flow filled a river canyon only to be attacked by erosion. The flow was resistant so new canyons formed on both sides, leaving the former bottom of a river as a ridge. It's a little tricky to see, but note how the land falls away on both sides of the road in the picture above. Some of the basalt crops out on the right. The rocks are the siltstone and shales of the Triassic Moenkopi Formation, one of the oldest layers exposed in Zion National Park

There are grassy meadows in Cave Valley, and intriguing "beehives" of Navajo Sandstone. The rounded dome-like forms aren't easy to see from the floor of Zion Canyon. At the end of Cave Valley we pass something unexpected: a cinder cone, Spendlove Knoll (below). It erupted about 220,000 years ago.

Why the volcanism? We are near the edge of the Colorado Plateau, at the faulted boundary with the Basin and Range Province of western Utah and Nevada. The stretching of the crust and subsequent fracturing of the rocks has provided an avenue for the molten magma to reach the surface.

The scenery is on a grand scale. I'm pretty sure that some of the scenes from the 1979 film "Electric Horseman" with Redford and Fonda were filmed here (a movie I loved, and apparently Willie Nelson's acting debut).

The road continues up the hill, passing between two volcanoes, Spendlove Knoll and Firepit Knoll. Firepit is about 290,000 years old. In the distance one can see the cliffs of the Kolob Canyons, another isolated and rarely visited corner of Zion National Park. The road passes back and forth through the boundary of the park; you always know you are in the park because the road turns red (from the use of red cinders in the asphalt).

The rock outcrops of the Jurassic Navajo Sandstone are striking. The sloping layers are the crossbeds I mentioned above. They form on the steep leeward faces of sand dunes (the slip face), and the distribution of the Navajo and related formations show that this sand dune field once extended from Wyoming to Arizona, and from Colorado to California. There is no place quite like it today anywhere in the world.

Where did all the sand come from? Much of it probably came from the remnants of the Ancestral Rockies, or the incipient highlands related to subduction off to the west, but recent research suggests that some of the sand was derived from rivers with headwaters in the vast Appalachian-Caledonian mountain system in what is today the southeastern United States.

The road makes a long and very steep switchback (10 mph!) to climb another escarpment, and suddenly we are in a thick forest of ponderosa, firs, and aspen trees. Even in summer, the meadows were alive with colorful wildflowers, despite the parched conditions on the valley floors below.

About three miles before Kolob Reservoir, a gravel road goes right towards Lava Point. I love the understated entrance sign for Zion National Park. There should be more like it. It was less than two miles to the campground and Lava Point Overlook at an elevation of 7,980 feet. At this point, the plateau is coated with basaltic lava erupted just over a million years ago, before the carving of Zion Canyon.

And we arrived at the overlook. The view, like so many others on the plateau, is expansive, taking in landmarks as distant as the Paunsaugunt Plateau of Bryce Canyon, the Kaibab Plateau and the North Rim of the Grand Canyon, and the endless Basin and Range. The valley floor of Zion Canyon is hidden deep in the folds below viewpoint.

The lush greenery of the forests contrasts strongly with the barren slopes of Navajo Sandstone. It's a verdant world largely hidden from the majority of park visitors who never get out of the deep valley. It is a sight that also helps to explain an odd phenomena that often occurs in the middle of the night when one is camped in Zion Canyon in summer. It is almost like clockwork; at about 2 AM or so, a cool wind kicks up in what had been a warm and sultry night. It is a drainage wind, a mass of cool dense air with a source on the high plateau that is flowing down the canyon.

We finished at Lava Point and faced a hot three hour drive back to Las Vegas, where our travelers would be catching flights home. We still had another day of driving back through the Basin and Range, and our trip would be over. Look for one more post about Zion, though. Even though we didn't see it on this trip, there is another spectacular corner of the park to seek out. 

Out in America's Never Never: A Corner of the Navajo Nation Where the Ancient Ones Dwelt

One thing I love about blogging is the total freedom be distracted and leave projects unfinished. This is something I inadvertently did six months ago. I got distracted by a river trip down the Grand Canyon and four field trip classes to the Cascades, the Sierra, and the California Coast. But I'm back to try and finish a series on my other incredible trip this last year: a journey through America's Never Never with a group of my geology students. You can catch up with the earlier posts by clicking here.

As I said in the original post, the Never Never is a remote and largely inaccessible part of the Northern Territory and Queensland of Australia's Outback. To some, it is a place that one would "never, never" want to go (despite this neat-sounding trip). To some of those who live there, it is a place one would never, never want to leave.

There are many parallels between Australia's Outback and the American Southwest, especially the Colorado Plateau. Most of the local populations live on the margins of the region, and until recent decades many parts remained unexplored by people of European descent. To others it has been home for thousands of years. The lands are ancient, each part revealing a fascinating geological story. And so it is that I refer to the Colorado Plateau as America's Never Never.

When we last left off the story we had explored Antelope Canyon, a deep slot canyon near Page Arizona. It was late by the time we finished our tour so the sun had set long before we arrived at our next campsite at Navajo National Monument on the lands of the Navajo people.

It was hard to get a sense of the country we had reached in the dark of the night, but when the sun rose I set out across the plateau to get a view of the countryside. Navajo National Monument is actually composed of three different units several miles apart: Inscription House, Keet Seel, and our location, Betatakin. Each of the units protects the ruins of an ancient people, the Ancestral Puebloans (once called the Anasazi). They were the "ancient ones" who lived on this land before the Navajo arrived hundreds of years ago. They abandoned the region 700 years ago; Their descendents live on the Hopi Reservation and the pueblos of New Mexico.

The land is unique. It is a high plateau called the Shonto that reaches elevations of more than 7,000 feet, which is high enough to support a forest of juniper and pinyon pines. The cooler forested highland is a stark contrast to the mostly barren deserts that surround the uplift. The plateau exposes Triassic and Jurassic aged sedimentary rocks, primarily the Navajo Sandstone. The Navajo is a major scenery maker in the region, responsible for the incredible cliffs in such places as Zion and Capitol Reef National Parks. The main drainage of this part of the Shonto Plateau is Tsegi Canyon, a deep gorge with an intricate maze of side canyons. Alcoves in the deep canyons protect some of the most perfectly preserved cliff dwellings to be found anywhere.

The alcoves are especially striking. There are impermeable layers of shale and siltstone within the Kayenta formation which underlies the Navajo Sandstone. Groundwater seeps downward through the Navajo and then encounters an impermeable layer. The water is forced to flow sideways until it breaches the surface at the base of a Navajo cliff. The cement holding the sandstone together dissolves and an alcove begins to form. It gets larger as slabs fall from the arch-shaped cavern. The alcoves turned out to be ideal spots for constructing villages. They are dry, protected from the worst of the weather, often have seeps or springs as a secure water supply, and offer superb defensive positions.

Defense? From what or whom? The Ancestral Puebloans lived in the region for well over a thousand years, but did not build the defensible cliff dwellings until very close to the time of regional abandonment. It's ironic that the most iconic remains of their culture represented not the pinnacle of their success, but the harbinger of their doom. It has long been the subject of speculation as to why the Ancestral Puebloans left the Four Corners area (except for the Hopi who continue to live in the general area). The speculation centers on a horrific drought that gripped the region in the late 1200s. Persistent drought would have led to ongoing crop failures and soil loss (as wind blew away dry topsoil). Starvation would presumably have led in turn to raiding and warfare.

Anthropologists, archaeologists, and the descendants of the Ancestral Puebloans have differences of opinion as to the reasons for the abandonment, but drought and resource depletion must have played a role. The villages at Keet Seel and Betatakin (in the pictures above and below) look like their inhabitants simply walked away, and the buildings have persisted in their protective alcoves through the intervening centuries.

We like to think in our technological bubble that we are somehow immune from such problems, but the need for water and food is still fundamental, and we are once again seeing the story unfold in the Colorado Plateau region of persistent decades-long drought. The present drought has now lasted 14 years, not far off from the 25 year drought that forced the Ancestral Puebloans to leave. The big difference is that the population that depends on water from the Colorado River now numbers in the millions, not the thousands. We can draw water from elsewhere, but drought is gripping California as well. It is a worrisome time.

One cannot explore the villages of Navajo National Monument without taking a stiff hike and the presence of a ranger/guide (Inscription House is closed to all visitation), but a short trail winds across the plateau surface from the visitor center to an overlook hundreds of feet above Betatakin. The preservation of the village is truly astounding, given our sorry penchant for destruction of all things ancient. It's a fascinating place to visit.