Podcast New Mexico Episode 4: the Chaco Phenomenon – Transcript

Hello and welcome to Distant Echoes. New Mexico Episode 4: The Chaco Phenomenon.

Last time we talked about the Mogollon, a culture that was contemporary with the Ancestral Puebloans. Today we will be shifting our focus back to the north in the Four Corners area. When we last touched base with the north, they had just begun to build above ground settlements in the Pueblo I.

Around 800 CE, while most Ancestral Puebloans were still living in the uplands, 3 special settlements were being constructed in the lowlands of Chaco Canyon. These were Pueblo Bonito, Panasco Blanco, and Una Vida. Other sites were located outside of the uplands, but they were mostly used seasonally, when the weather permitted. These settlements sat at a rather unique position as around 800 AD rainfall became more bimodal between winter and summer with areas north of Chaco Canyon getting more rain in the winter while those south would get more in the summer.

As a reminder on dates, Pueblo I has been determined to have lasted from 700-900 CE. However there is some overlap between Pueblo I and Pueblo II.

Around 830-840 CE Pueblo II began, more settlements began to be built, covering about every inch of farmable land, however these settlements were often abandoned. Having more settlements along more farmable land meant there was more dependence on dry farming, which meant when years were bad in one area it could be offset by trade with a different region. Chaco Canyon is believed to have become the hub of this expansion.

Around 900 there began to be a migration into the lowlands, hoping to get to areas for better farming. This appears to be a response to growing competition from farmers. These farmers either pushed the remaining hunter-gatherers out of the region or forced them to assimilate into the new society that was building. Often sites were periodically abandoned, people only returning with the rains.

By the 950s, the early locations that helped Chaco Canyon grow like the Red Mesa Valley and Chuska Valley were already at their maximum capacity. Around this time, Pueblo II had become standardized. Few of the sites found from this period were very large. There are signs of episodic starvation in childhood for those born in the 980s or 90s based on remains found.

Around this time Chaco Canyon itself began to take on a much larger scale with grander projects rather than just raw growth. In this time, the Late 900s early 1000s, the Great Houses for which Chaco would become known began being built as well as the beginnings of their road system. These planned settlements aligning with certain astronomical observations imply that some form of social hierarchy was beginning to appear. But there are no signs yet of a warrior class or much concern for defense at all. The great houses were open settlements, walls not being built there until much later.

The remains of big game also become scarcer around this time. This could be because of overhunting by Chacoans, climate change, or both.

Luckily for Chacoan society, around 1000 the rains got more predictable. This allowed for the Chacoan system to begin growing even more, expanding even further along the San Juan Basin. This is when the Chacoan Phenomenon, as it’s called, begins. This Phenomenon is described by rapid population growth and expansion outwards centered around several small locations. The entire region shares the same material culture at this time.

By sometime between 1020 and 1130 almost every pit structure had been converted to a kiva. In the later 1080s-1100s most of the tower kivas were constructed. For those that don’t know, a kiva is a ceremonial or communal structure among the Puebloans. Often they are circular and underground with a bench lining the wall. A tower kiva is believed to have served a similar purpose just above ground and with multiple floors. 1080-1090 is also when Chaco Canyon was at its height in both size and power. It covered a truly mind-boggling area of 40,000 to 50,000 square miles. Roughly the size of Scotland or Portugal. This also coincides with a period when rainfall began to decline.

In 1090 a severe drought struck the Chacoan area and lasted for about five or six years. This is roughly as long as the Dust Bowl.

Around 1100 we entered the next major phase, Pueblo III also known as Great Pueblo. This is when settlements began to be carefully planned and great work projects were undertaken. Furthermore, the burials found in the great house population are taller and significantly more likely to survive compared to those at farmsteads. In some ways, this period could be considered the peak of the Chacoan system.

They built great road systems in all directions connecting to other great houses and settlements. It is believed that beyond some practical purposes they served, they also were ceremonial as they are far wider than they needed to be for just foot traffic and there are many stops along the way. Some of these stops appear to be horseshoe shaped shrines called herraduras. These roads were extremely straight, often going through obstacles rather than around them. One theory, proposed by Pierre Morenon for why they go through these obstacles is that by investing the manpower now to build these roads, the Chacoans were able to lower their calorie count when transporting goods significantly. Morenon decided to test this and found that the roads reduced caloric use by 38% compared to traveling across the landscape without them. Another theory as many of these roads were built in the later 1100s is that they were public work projects. Much like the projects of the CCC or WPA during the Depression, ways to support farmers during extended droughts.

The full effect of the 1090 drought is unknown, but it appears to have taken the wind out of the Chaco Phenomenon’s sails. It was quickly running out of steam. The last major roof beams for the great houses have been dated to 1116 however some minor refurbishment may have taken place around 1130.

The 1100s show clear signs of resources declining. People began to move out of the Chacoan core, building other great houses like Salmon or Aztec. The latter actually being where the title picture for this podcast was taken. Salmon was abandoned sometime near 1150 until being reoccupied again in the 1200s.

There was however one final wave of great houses, finished by 1139. These may have been public works as the Chacoan world tried to expand just a little farther into poorer farmland. Perhaps they were just trying to prop the whole thing up long enough to survive? Perhaps it was the elites trying to start again on the fringes of the system. Trying to return to the old to fix the issues of their time.

Either way, by 1100 most of the great houses were abandoned and the heart of the Ancestral Puebloan world had shifted north to the San Juan River, southwestern Colorado, and Mesa Verde.

So why did the Chacoan system 300 years in the making fail in only 40 years? One theory is that the extended drought of the 1090s was just too much for the system to handle despite its best efforts and made people disaffected with the current social order. I’ll lay out the reasoning and evidence in steps.

Over the 1090s at the height of the drought, farmsteads begin to be abandoned. At the same time even greater work projects were launched and some more investment was made in wet farming, some irrigation systems even being built in the Chacoan Core. Could this have been a way for the Chacoan elites to try and keep the economy above water until the rains returned? It is implied multiple teams were working on these great houses at the same time as some corners don’t quite line up. Like two different teams were working on it and used different units. However these projects probably did not bring in as much usable land as previous expansions and were unable to help the ailing system, people were still going hungry.

Around 1100 a change takes place, the Great Houses are walled off and warrior burials begin to appear, often having died a violent death. This implies significant social disorder going into the 12th century. However the Chacoan system was able to limp along to the 1130s, with the last roof beam being placed at Bis Sa’ani in 1139. However another drought hit during the 1130s from which the system centered on Chaco Canyon could not recover from.

Another theory is that the Chacoan Elite simply became too disconnected from the common person. These great building projects weren’t to prop up the economy, instead they were to show off the great wealth of the elites. Like a certain French monarch partying while the people starved, at least in the popular perception. For instance in the 1100s, a woman in the Red Mesa Valley would have to have four children just to maintain the population.

While Chaco Canyon’s great houses had only ⅓ of their space for living and the rest for storage, an uptick over time. The farmsteads were storing roughly the same amount. Leading up to the 1100s there is also clear evidence of trade with Mexico, with chocolate and macaws skeletons being found. However After 1130 these luxury items are all gone.

Faced with this and failing harvests, the farmers decided to just leave, hoping to find greener pastures in their Ancestral homelands; others may have become laborers on these great projects.

As Chaco Canyon’s focus was on storage and ritual, the farmsteads in the core area weren’t as productive as those outside of it so the core was thrown into chaos.

Facing this chaos, some elites begin to leave, moving towards the San Juan and Animas rivers to the north. There they build Salmon and Aztec. But these would eventually fail.

Meanwhile, the farmers had moved into the more sparsely populated uplands. Few were building farmsteads however, and those that were built them in isolated locations. Far away from other people. This implies that violence was rampant even in the uplands. This could either be due to the hunter-gathers already in the uplands or due to others displaced from Chaco Canyon. Some of those already in these areas seem to have had no connections with Chaco Canyon at all.

Pit Houses also make a re-emergence and more displaced populations move upwards to obtain more annual rainfall. 1130-1150s were the most violent periods in this migration, some bodies show quite violent deaths such as dismemberment or having their skulls crushed. By the 1170s however, the violence began to taper off.

Essentially, Chaco cracked along the line of those who had more and those who had none. Those who had more tried to carry on the status quo in new lands while those that had none moved into their Ancestral homelands in hopes of finding new farming and escaping the violence. This is backed up by the lack of red Mesa Valley pottery in the northern settlements where it does exist in the upland settlements. Times were hard, Turkey were eaten young and more wild plants appear in the diet. Some researchers suggest a return to a hunter-gatherer lifestyle among some groups at this time.

By 1170, other than maybe around Aztec Chacoan Society was simply a memory.

Another theory for the fall of Chaco Canyon is that nomads arrived. While it used to be thought that the Athabaskans, the linguistic group that the Navajo and Apache belong to, didn’t arrive in the southwest until closer to 1400, it is quite hard to track them and some evidence has shown that they could have been in the southwest some time in the 1100s-1200s or some other Nomadic group arrived. They could have been raiding the farmsteads and incentivized the change to more defensive structures. That mixed with droughts could have stressed the system past its limits.

Another theory is that the position of Chaco was simply displaced. As we talked about in the last episode, in the 1030s Casas Grandes was on the rise. With it being closer to Mesoamerica it may have simply supplanted Chaco Canyon in the trade network, much like the Mimbres Valley we talked about last episode. This decrease in trade could have caused the expansion of the system to its limits as Chaco Canyon tried to compete before a drought caused it to fail.

The final theory that we’ll talk about is, as my mother would put it, the outgrowing the petri dish. Put simply, the Chacoan farmers exhausted the land they were farming by not allowing fields to lay fallow to support the growth of the system. This depleted the soil leading to smaller crop yields and when a drought hit, there just wasn’t enough food to go around. Some expansion was attempted to keep the system afloat but it just was too little too late. This led to a system wide collapse and the outbreak of violence as those without food tried to take it from those who did by force. It is even possible that Chaco was made up of many different ethnic or linguistic groups and when times got hard, violence broke out among these lines.

All of these theories have some evidence to back them up; be it the climate change, migration of new people, the rise of a better placed competitor, disconnect among the haves and the have-nots. I find a mix of all of these compelling; climate change, new trading competitors, and exhausted soil led to unrest and famine. This pitted the different groups be they the haves and the have-nots, different linguistic groups, or new arrivals in the area. There were pushes to try and expand to new farmland and public works to try and keep the economy afloat but these were not enough to keep the population afloat on their ailing overpopulated farmsteads.

Some of these farmers finally said enough is enough, after all, how many of your children do you need to bury before you decide to take your chances elsewhere, especially when the elite’s children are much more likely to survive. As more people began to opt out of this system and take their chances elsewhere, or were displaced by the violence in the area, some moved north to build Aztec and Salmon and try to start over. Those opting out of the system also created less people trying to farm and provide the food needed to keep the system afloat, leading to a vicious cycle.

Finally, those displaced and moving into the uplands encroached on land that others were using, leading to further violence.

Either way, in the 1170s, things would once again change as the violence abated and trade opened up. But we’ll talk about that in the next episode.

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1 Response

  1. Heidi says:

    What was the advantage of the bimodal weather system? Is there more information about the faming system? Why would eating a young turkey indicate that times were hard? Were turkeys kept for eggs? How domestic were these turkeys? What where they faming? How did they get their seeds? Is there evidence of Chaco being a religious center in addition to a trade center?

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