Yes, Mesa Verde is the richest archaeological preserve in America. A sanctuary of cliff dwellings. Petroglyphs. Thousands of sites holding clues to an ancient civilization. But is it too much to ask for better cell phone reception?

For two days, my wife and I meandered around the park and its environs, climbing with other tourists among the 40 rooms of Balcony House, visiting dozens of kivas—rooms for religious rituals—and walking among striped pieces of broken pottery, or “sherds,” that litter the place. But it wasn’t until we retreated to the park’s Spartan lodgings, also called kivas, that we could tap the wi-fi and fill our mitts with the twenty-first century’s throbbing stream of news and email. The daily information void made me feel like echoing one of those irony-laden, one-star Yelp reviews. Death Valley is a desert! Yosemite has crappy parking!

I feel badly about this. Would that I could glimpse the world of the ancients—connected to nature and the cultural and historic grandeur of a place—without reaching for my technological binky.


Except this place is a marvel of technology. Its innovations span centuries. They gave rise to not one culture but several, over several distinct eras. They include a massive architectural development that is unlike any seen among prehistoric societies. The cliff dwellings, tragic emblems of the need for protection against lethal enemies, are only their most famous of feats. Coming at the mysterious end of an era, after which almost no one lived here, the dwellings are only one in centuries of invention. They are the violent exclamation mark at the end of a long, powerful sentence.

Ancestral Pueblo people abandoned the elaborate cliff dwellings of Mesa Verde sometime in the late thirteenth century, creating a mystery that The New York Times has called “the most vexing and persistent question in Southwestern archaeology.” Tim Kohler, a Washington State University Regents professor of anthropology, has pondered this question for some four decades, but it has only been one of several questions. He has also wondered about the human impact on the environment, why people choose to live where they live, how they share public goods, how they deal with inequality.

He can ask so many questions because the region has a rich record, a trove of data and artifacts so substantial that a researcher can explore numerous hypotheses and lines of evidence. The evidence is sizeable, with much shoveled, troweled, and analyzed by a long line of WSU researchers. With Kohler, WSU anthropologist Bill Lipe led the Dolores Archaeological Program, one of the largest excavations in the world. Both he and Ricky Lightfoot ’91 PhD were instrumental in running the Crow Canyon Archaeological Center, a “living classroom” devoted to researching, teaching, and preserving ancient Pueblo history. Carla Van West ’90 did pioneering work on the effect of historic climate changes on agriculture in the region.

With Crow Canyon, Kohler led the National Science Foundation-funded Village Ecodynamics Project. It is a technological marvel, testing computer-driven scenarios that reach back in time against the region’s voluminous data archive. It’s a process common to most of science but largely foreign to archaeologists. They can’t make happen in a lab what happened hundreds of years ago. But Kohler can make finely-scaled predictions and test them against records of climate, precipitation, settlement, and other clues.

Just last year, he and Kyle Bocinsky ’11 MA, ’14 PhD, used data from 1,000 Southwest archaeological sites and nearly 30,000 tree ring dates to chart year-to-year changes, including climatic changes, spanning 900 years. Published in Science Advances, their study focused on the exploration and exploitation of niches—places to live, the technology needed to do it, and ways of organizing, often through rituals, to cooperate and get things done.

Their approach was so data-intensive that it required climate reconstructions at a national supercomputer. If they wanted, they could have done all the work without ever touching a sherd. As it was, Bocinsky, while no stranger to field work, collected none of the data he analyzed.

“Twenty years ago, they would not have let you do that,” says Mark Varien, Crow Canyon director of research and a frequent collaborator with WSU researchers.

Bocinsky and Kohler concluded that the depopulation of Mesa Verde after 1285 was only the most severe of four population crashes in five centuries. Cultures came and went, often in response to the vagaries of a changing climate, but from their inception, technology had an outsize role.

Consider corn.

For millennia, largely nomadic people in the Mesa Verde region of western Colorado and corners of New Mexico, Arizona, and Utah lived off game. Corn had been in Mesoamerica since 5000 BCE and in the Southwest since 3000 BCE, but the maize in what is now Arizona needed its feet in water, says Kohler. To survive on the mesa tops to the north, it would need to grow in colder conditions and mature faster, with less rainfall.

Around 600 CE, a new corn appears in southwest Colorado. It is more productive than earlier varieties, with wider, larger kernels, which are also easier to shuck and grind.

“They basically have a lot more starch in them,” says Kohler. Starch has a higher glycemic index than earlier corns; women can put on fat, ovulate more, have more kids. The Mesa Verde area gets its first substantial population of year-round residents. Birth rates start to rise and late in the eighth century, villages appear.

Eaten with beans to make a protein of all nine amino acids, corn became the ancestral Pueblo meal ticket. Throw in ceramic pottery and permanent dwellings, and the people of the region had the “Neolithic package,” the suite of developments that fueled a flourishing society.

“By the time the Neolithic gets up to southwestern Colorado, it’s all been put together,” says Kohler. “It includes a bow and arrow. It includes efficient ceramic containers. It includes beans. It includes a more productive variety of maize.”

Technological changes in ancient Pueblo society have served as organizing principles for archaeologists since 1927, when 40 or so of them conferred in Pecos, New Mexico, and laid out eight distinct periods or “cultural stages” of the region’s prehistory. The first three were Basketmaker I, II, and III, followed by Pueblo I, II, and so on up to Pueblo V.

Pueblo societies - Timeline

The early Basketmaker periods spanned the changes from semi-nomadic hunter gatherers to settled agrarians with bows and arrows instead of spears. In the Pueblo eras, the people moved into masonry dwellings whose changing sizes and arrangements offer insights into the shifting prosperity and social relations of their time.

Basketmaker III, which ran from 600 to 700 CE, featured great kivas and dance floors, as well as underground grain storage. It ended with a mild drought. In the ensuing Pueblo I, the people moved their grain storage to above-ground chambers. Kohler and Bocinsky interpret this as a shift from people freely sharing food to more tightly controlled exchanges by households or family groups. This period ended around 890 with a slightly larger drought.

Pueblo II was a heyday of sorts, judging from its architecture. It was the era of what archaeologists call the “Chaco world,” a large, complex social system that grew out of Chaco Canyon 100 miles to the south in northern New Mexico. It was filled with huge plazas and houses, the largest being the canyon’s Pueblo Bonito, a complex of 600-plus rooms some 300 years in the making. Kohler calls it “the largest masonry structure in North America at the time, in fact, ever built up until something like the nineteenth century.”

But while it is the biggest known great house, it is one of many. Remains of more than 200 others have been found in the northern Southwest. Bocinsky, now director of sponsored projects for the Research Institute at the Crow Canyon Archaeological Center, lives next to the remains of one.

In many ways it looks like so much rubble. What looks like a passageway between two walls is actually a gap created by a bulldozer when the site was, as Bocinsky puts it, “nonprofessionally excavated for commercial purposes.” As the excavation was done by a previous landowner, it can’t be called looting.

It takes some imagination, but the house once covered the length of a football field. It also has a great view, with Mesa Verde to the south, Ute Mountain to the west and a vast sky full of clouds and virga. Ancient Pueblo people were on intimate terms with their environment, looking to it for sacred touchstones, hunting signs, cues for planting and harvest, and physical reminders of one’s place and identity.

“When you didn’t have Google Maps, this is all you had,” says Bocinsky.

To Kohler and Bocinsky, the mix of large and small buildings, room sizes, and varying access to food in the Pueblo II era suggests a more hierarchical social structure with someone in charge. People are staying in place longer, sometimes decades. This has implications for one’s inheritance. The children of wealthier parents are more likely to be wealthier, so differences can accumulate. As a result, Kohler and Bocinsky see a world of haves and have-nots, of mounting inequality and social tension.

Add climate change to the mix, and there is a potentially combustible situation.

“These niches are woven together with a web of ceremony and ritual that requires belief in the supernatural and belief that people who are enacting the rituals know what they are doing,” says Kohler. “If they know what they are doing, that will bring the rains so there’s plenty of food and everybody is living well. But if the ceremonies are conducted but everybody’s starving to death, something is clearly wrong. So those rituals become what we call ‘delegitimized.’ Then there’s a point where people say, ‘This isn’t working. We’re leaving.’”

Kohler and Bocinsky’s analysis saw that happening four times.

“Their leaders are telling them, ‘This drought is going to get better, things are going to get better. You just stay right there,’” says Bocinsky. “And at the same time, those leaders are feasting on deer. They have plenty of corn. You get this amplification of inequality and at some point that breaks, that snaps, and the thing that seems to snap in each of these four periods is a climate downturn that’s a little bit worse than ones that people have been dealing with before and it just makes them say, ‘We’re getting rid of it all. Throw it all away.’”

The fourth time was brutal.

“In none of the previous ones was there a depopulation of the entire northern Southwest,” Kohler says. “There were certainly local
population crashes but never did you lose everybody out of the northern Southwest.”

The end of Pueblo II, the third period in their study, saw the Chaco world fall apart. Without its socially unifying effects, tensions were more likely to produce outright conflict. Whatever the reason, the region saw a wave of horrific violence. Between 1130 and 1180, the region saw its longest and most severe drought. Kohler has documented how nearly nine out of ten sets of human remains from the last 40 years of that period have trauma from blows to either their heads or parts of their arms.

In Pueblo III, the people built the Mesa Verde cliff dwellings. Even today, they are striking works of architecture with a natural intimacy cultivated by architects centuries later. But they are at heart defensive structures, hard to attack from above and with removable ladders to keep out enemies from below.

The end game is unclear, but a pretty good picture has emerged in the last decade or so. The so-called Great Drought ran from 1276 to 1299, starting what Kristin Kuckelman, a Crow Canyon archaeologist, has called “a downward spiral of resource competition, hunger, strife, and warfare.” The land was played out after 700 years of farming, says Kohler. Corn was now 80 percent of the diet, and much of the crop was going to feed domesticated turkeys, yet another of the Pueblo innovations. The cliff dwellings offered protection, but their existence suggests it was dangerous to tend to the fields above. Across the region, archaeologists have found numerous human remains with similar skull fractures, presumably from stone axes found at sites from the period.

In the late 1200s, the region sees the first population decline in 300 years. People are abandoning dearly held farms for the more placid northern Rio Grande Valley to the south. They’re also not living as long. Things have fallen apart. As many as 10,000 people may have lived in the region in 1260. But after 1280, they are no longer cutting the wood that provided tens of thousands of tree ring dates from the region. They’re likely gone.

It’s tempting to see parallels to contemporary society, particularly in light of climate change, growing disparities in wealth, and the sense of disenfranchisement voiced around the recent presidential campaign.

“We still freak out when oil changes price,” says Bocinsky. “We still freak out when the cost of certain grains fluctuates. Corn is actually so essential to the global economy that it’s almost silly that we’re talking about corn still.”

“We think we’re immune to all those things that happened to Pueblo society because we’re so technologically sophisticated,” says Kohler. “Maybe by their standards, they thought they were technologically sophisticated too. But that didn’t necessarily prevent things from falling apart in the 1100s. It didn’t prevent the Pueblo I villages from falling apart in the late 800s. It certainly didn’t prevent the Pueblo III villages from falling apart in the late 1200s.”

Kohler hopes there is a lesson in there.

“Societies are prone to falling apart,” he says, “and if we value our well-being as individuals, we will attempt to forestall those crises that cause societies to fall apart because they’re often accompanied by great violence and great hardship for the constituent members of the society.”

View of Mesa Verde from the northView of Mesa Verde from the north. Photo WikiMedia Commons