Monday, December 13, 2021

Ancestral Puebloans and Climate Migration


The Dollhouse Ruin in the Bear's Ears region.
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The U.S. desert southwest is remarkable in its concentration of archaeological sites, relics of the Ancestral Puebloans who occupied the Four Corners region until about 1300 AD when, somewhat mysteriously, they left. Anthropologists have pondered the abandonment of places like Cedar Mesa, Chaco Canyon, and Mesa Verde for over a century, and many theories have emerged to explain why these people abandoned elaborate structures and a well-developed civilization. The simplest explanation is that a “megadrought” in the late 1200s drove them out, but hypotheses are more nuanced, invoking resource depletion, violence from both within and outside, the breakdown of complex religious hierarchies, and increased vulnerability to environmental change caused by reliance on agriculture, to name a few. 


Reliance on corn may have been a mixed blessing for Ancestral Puebloans because of increased vulnerability to changes in climate. (Comb Ridge, October 2021).

A granary on Cedar Mesa used for storing corn. (October 2021)

There is general agreement that by 1300, most of the sites across the Four Corners were abandoned. Evidence suggests that the Ancestral Puebloans migrated south and integrated with Hopi and Zuni peoples and other groups in the Rio Grande drainages, though it is still unclear why they moved from one dry place to another. What is clear is that environmental pressure led to a breakdown in society that culminated in abandonment and migration.

Masterfully constructed structures at Hovenweep National Monument, Utah. Why were these built on boulders? (October 2021)

A ruin at Hovenweep as a storm builds in the distance. (October 2021)

While I was in the Southwest this fall, I read Douglas Preston’s book, Talking to the Ground, about a 400-mile horseback trip he and his family took in 1992 across the Navajo Reservation, tracing creation stories and talking with Navajo people along the way. In his 2019 epilogue, Preston espouses the idea that Chacoan power hierarchy depended on the belief that religious leaders controlled the rain, a strategy that worked well for them in wet years but not so well when multi-year drought inevitably arrived. This led to violence and the breaking of bonds holding geographically disparate groups together. Though theories continue to evolve, the gist remains the same—drought-caused stress catalyzed changes leading to abandonment of vast areas and dissolution of a well-developed civilization. Preston writes: 

“What we know is this: one thousand years ago, the Anasazi embarked on a great religious experiment at Chaco Canyon, an experiment based on the (illusory) control of nature. It was an experiment whose ultimate consequences the Anasazi did not foresee. And it failed.” (Preston pg. 261) 


Ruins at Chaco Canyon (June 2018).

The well-known Citadel ruin on Cedar Mesa. Did ruins become more defensive as resources became scarce? (March 2016)

2008 New York Times article by George Johnson acknowledges this idea but suggests that abandonment may have been less sudden, though still ultimately driven by changing environmental conditions. The article concludes:


“Amid the swirl of competing explanations, one thing is clear: The pueblo people didn’t just dry up and blow away like so much parched corn. They restructured their societies, tried to adapt and when all else failed they moved on.”


We still have marks on door trim in our house showing our daughter's height as she grew up. Maybe the handprints above this dwelling were the same. We think of ancient migrations in the abstract, but these were people like us whose lives were uprooted. (Cedar Mesa, March 2017)

Migrations in response to changing climate were not new, even in 1300. The populating of the Americas was mediated by the last ice age as people crossed the land bridge from Asia and walked southward. Further back, there is evidence that waves of migration of Homo sapiens from Africa into southern Europe beginning almost 100,000 years ago may have been driven by periodic climate changes that opened green corridors between Africa and the Arabian Peninsula.

Humans have always moved to more favorable environments when they could.

In September (2021) on our way to SE Utah to camp, hike, and visit ruins, we drove along I-70 in Colorado through the heavy smoke of the 2021 fire season, entering Glenwood Canyon where an extensive wildfire the previous year had denuded the canyon walls of vegetation. Earlier in the summer, unusually heavy monsoon rains generated enormous landslides, trapping people in their cars, briefly damming the Colorado River, and decimating parts of the highway, which was still being repaired months later. We arrived in Utah during an unseasonable heat wave and sweltered for several weeks before it finally cooled down. These extremes—wildfires, torrential rain, landslides, heat—are signs of a changing climate, but unlike the changes in the 1200s, modern climate change is global, not regional. 

Even in 1995, Douglas Preston and the Navajo people he visited were aware of modern parallels to the Chacoans:


“As the twentieth century draws to a close, we find ourselves in a similar effort to control nature, only this time on a much larger scale. Our experiment is not based on ritual but on technology. We believe, as the Chacoans did before us, that we have gained a certain mastery over nature. Our God gave us dominion.


The question is: have we really achieved it? Could our mastery of nature be as much an illusion as the rain ceremonies of the Chacoans? Are we, like the Anasazi, headed for an environmental or technological disaster?” (Preston pgs. 261-262 of )


Today, Preston’s last question seems quaint. The answer is clear, but still we struggle to respond in a meaningful way to the increasing concentration of greenhouse gasses we spew into the thin film of atmosphere clinging to the earth.

Wildfire smoke during the Mullen Fire west of Laramie, Wyoming. Smoky summers are part of our lives now. Ten years ago they were the exception. (September 2020)

During his journey, Preston speaks with a Navajo man named Edsel Brown. The Navajo, who themselves once migrated from the northwestern North America to the desert, believe that the earth is a living relation rather than a “resource.” Edsel Brown tells Preston (emphasis at the end is mine):

“This cycle goes back to a long time ago. It goes back to the first invention that was created. It goes back to when the Bilagaana [white man] realized that they had the power to make things. They had the power to create things. And they started to look on the land as a resource. They didn’t look at the land as relatives, as living beings, which it is. And they made these inventions, electricity, dams, cars, bombs, pesticides, everything. They kept thinking that all these inventions would help them. And yet, they’re still not helping them. And now, today, things are starting not to work for them, and they have no place to go, and they have a hard time realizing what is happening.” (Quote from a Navajo man, Edsel Brown in Preston, pgs. 263-264)

It’s hard for us to see changes that happen over decades or centuries, but the effects of climate change are increasingly obvious. Are we creating our own ruins? Who will visit them?

Ruins and graffiti at an abandoned industrial site in Laramie (2011). Where will we migrate?



Friday, December 10, 2021

Mountain Biking: The White Rim

Looking out over the first part of the smoky, hot (90s) White Rim from the Shafer Overlook. 
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On the first of three nights spent on the White Rim Trail we camped at the exposed Airport site, and after dinner, the 90+ degree cloudless day gave way to violent wind and lightning. We did our best to hold our tents together. I plastered myself against the windward wall of our Big Agnes Copper Spur 2, while Ellen lay on her back supporting the poles with her feet and the opposite wall with her arms. One pole snapped and ripped through the fly, but we stayed mostly dry even as blowing sand filtered through netting onto our pillows and sleeping bags. After more than an hour of wind (60 mph? 70mph? more?) and just enough rain and hail to turn the dust to mud, the storm moved on, and we reunited in the dark with our friends to assess the damage, comb the desert downwind of camp for lost crap, and compare stories. Despite the violent storm, it never got even remotely cool.

The trip included eight of us from all over the West (Laramie, Boulder, Ft. Collins, Bisbee, Seattle). We mountain biked the route over four days in mid-September, when temperatures each day hovered in the 90s and low 100s, well above "normal" for that time of year, but not that unusual either. 90s and 100s are less ideal than other temperatures, but despite the heat and wildfire smoke, it was a very fun trip--much more fun, for example, than the plethora of pandemic-spawned Zoom meetings (graphic below) all of us have faced.

The world has changed since the last time I was on the White Rim decades ago. Mountain biking wasn't even a thing then, when, with no permit required, friends and I camped for a week in Taylor Canyon to climb Moses and Zeus (sandstone spires) and didn't see another soul. Moab, then relatively sleepy, is now a hellscape of ATVs, traffic, tourists, hotels, restaurants, and t-shirt stores; it's hotter and smokier in the West every year; covid rages; and mountain bikers (including us) are everywhere. Despite that, the White Rim remains beautiful and uncrowded. What a pleasure, even in the heat, to ride with good friends along the Colorado and Green Rivers, past Wingate cliffs with spires coming into view around every corner and good meals at every camp. 

Here are a few photos from our trip, and a little information follows on logistics. 

Daytime temperature on the White Rim vs. Enjoyment. (graph concept copied from

(L to R): Me, Ellen, Brian Collins, Larry Scritchfield, Allie Ruckman, Ben Leonard, Bret Ruckman, Judy Ruckman. We were barely sweating at all before we started riding.

Shafer Overlook: Larry looking down at the Shafer switchbacks--the descent route to the White Rim. 

Day 1: Bret pointing out Crow's Head Spire, a climbing destination. We camped on the rim near there after finishing the 4-day ride.

Day 1: White Rim sandstone capping mini-spires along the rim. 

Day 1: Musselman Arch. Walking across it is prohibited, but rumor has it that it's been traversed by ATVs (and probably motorcycles). 

Day 1: One of many enticing canyons cut into the White Rim. The heat kept us from getting too enticed though. 

Camp 1: Not so ominous (we thought) storm clouds gather near our first camp at the exposed Airport site. After we retired for the night, the storm unleashed 60-70 mph wind and rain, hail, and lightning for over an hour, during which we all fought private battles to keep our tents from being tattered and rolled across the desert. It was engaging and amusing.

Camp 1: Larry (R) and Brian (L) set up their tents at the Airport site. Unlike some of us, they had the wisdom to attach their tent flies BEFORE the wind reached tropical storm force.

Camp 1 (morning): The next morning, Ellen (L) and Judy (R) compare notes on how to hold a tent up with your feet in 60+ mph wind.

Camp 1 (morning): The storm-battered crew prepares for the second day of riding. 

Day 2: Bret riding with Monster and Washer Woman Towers in the background.

Day 2: Allie and Judy share the shade of an umbrella. My umbrella self-destructed at our first rest stop on day 1 ($5.99 just doesn't buy the quality it used to), so I was left with only my hat for shade.

Day 2: Bret standing on the rim of an enormous alcove undercutting the road/trail.

Day 2: 90s? 100s? Shade?

Day 2: Ellen approaching the steep climb to Murphy's Hogback near the end of the second day of riding.

Danny McGee, our sag driver. He works occasionally for Rim Tours, a Moab outfitter. Rim Tours was great to work with, and Danny was incredibly accommodating and patient as we wobbled along in the heat. He's a climber and knew Bret from Boulder, so there was an immediate connection.  

Camp 2 - Murphy Hogback: We camped on top of the Murphy Hogback after walking our bikes up the steep hill that leads up it. We enjoyed great views from the camp and no more storms.

Camp 2: Bret organizing his and Judy's tent on Murphy's Hogback as the sun set. 

Day 3: Watching freshwater shrimp in a pothole at Black Crack. Black Crack is a deep fissure that runs parallel to the rim for hundreds of meters where a part of the White Rim sandstone is separating from the rim.

Day 3: Brian taking refuge in a rare spot of shade on a day when a passing 4WD group told us it was 103 degrees. 

Day 3: Lunchtime in the shade where the trail crosses the Holeman Slot. After lunch, we descended partway down the slot, which was shady and full of pools of water. 

Day 3: Bret spotting Judy on a downclimb in the slot. With muddy feet, The slab below him was the crux of the climb out on our return.

Day 3: Fixing a flat tire in the shadeless desert.

Camp 3: Sundown at Hardscrabble Bottom on the Green River, our last camp. After a day of riding in 100+ degree blazing sun, we lowered our body temperatures in the Green River and sat in the shade of an awning drinking beer.

Camp 3: Bret with bacon! Breakfast on our last day.

Day 4: Sunrise. Hardscrabble Bottom.

Day 4: Allie and Ben ride along the Green with youthful enthusiasm on the last day. Morning shade made youthful and oldful enthusiasm more achievable.

Day 4: Back to the car shuttle at the top of Mineral Bottom.

Camp -- post trip: Crow's Head Spire from the rim (see earlier picture). Ellen and I camped with Bret, Judy, Allie, and Ben near here before we all headed off in different directions.


We rode from Shafer to Mineral Bottom, which seemed good, but people ride the other way too. 

There's no shortage of information online about the White Rim (see links below). The challenge is reserving well-spaced campsites along the way; our strategy was for 3 of us to hover over our keyboards on the day they opened up reservations for the time slot we wanted. The camps we got (Airport, Murphy's Hogback, Hardscrabble) were pretty good--Murphy's was great. White Crack seems to be the camp everyone wants to get, but we weren’t fast or lucky enough to grab it. 

We paid Rim Tours to sag our trip so that all of us could ride every day and to save our own vehicles from the rough road. Most of the road was good, but the climbs up Murphy’s Hogback and Hardscrabble Hill seemed a little gnarly, and there were some deep mud holes on the last day. Presumably, the road gets graded now and then (??), but I was glad we didn’t drive it ourselves. 

We bought food as a group and took turns cooking and cleaning up. That worked well on our trip, but required a lot of planning with a big group. The alternative would be for everyone to buy their own food and cook for themselves. That choice is just a matter of group preference. 

See the following for more info: