Archaeology

The Chaco Phenomenon

Chaco Canyon is a mystery. As Stephen Lekson writes in Chaco Meridian:

Chaco has long been the bête noir, deus ex machina, eight-hundred-pound gorilla, and in-room elephant of Southwestern archaeology ... What was Chaco? Archaeologists despair, pronounce Chaco an unsolvable mystery.

So what was Chaco? According to Lekson:

There are some evident facts: Chaco was big. It was showy. It was expensive. Its architecture was clearly stratified (in the social sense): "Great Houses" were high status buildings on one side of the canyon, and small, modest, lower-status "unit pueblos" huddled on the other. Not many people lived in the Great Houses, and those who did were buried with pomp, circumstance, and possibly retainers, or more likely, descendants in a family crypt. Much of each great house was designed for functions other than gracious living: warehouses, offices, ritual, maybe even barracks. Anywhere else, Chaco Great Houses would be called "palaces," but that term seems incongruous--even indecorous--in the Pueblo region. Get used to it: they were palaces.

These supposed palaces sit in what is now called Chaco Canyon (about 60 miles from Gallup, New Mexico). It’s a harsh, desolate, and unforgiving place: whenever it's cold in northwest New Mexico, it's always a few degrees colder there. Whenever it's warm in northwest New Mexico, it's always a few degrees warmer there. There are no real rivers that go through there. So what is so special about Chaco Canyon? Well, amongst other things, this:

Pueblo Bonito (taken by me). For scale, that’s a person next to the central kiva.

Pueblo Bonito (taken by me). For scale, that’s a person next to the central kiva.

Pueblo Bonito (image taken from Google Earth).

Pueblo Bonito (image taken from Google Earth).

Here’s an artist’s rendition of what Pueblo Bonito would have looked like around 1000 years ago:

What Pueblo Bonito would have looked like 1000 years ago.

What Pueblo Bonito would have looked like 1000 years ago.

That's Pueblo Bonito — the main "Great House" and, by some accounts, the largest public building in North America until apartment buildings were constructed in 19th century Chicago. Around 400 to 1000 people lived there. Construction at Chaco Canyon started around the 9th century and was completed by the end of the 12th century. And the presence of that Plaza Tree — a “majestic ponderosa pine” — requires its own explanation.

Whether the Great Houses are palaces or not seems to be an open and controversial question, partly because palaces imply states, and states imply a form of social organization wherein some group has a monopoly on socially sanctioned violence. Such a picture seems at odds with our romanticized views of ancient Pueblo culture as an idyllic and peaceful state of nature. But we know that this is wrong: “Massacres, raiding parties, ambush, scalping, and captive taking … happened in the prehistoric Southwest.” Nevertheless, Lekson claims that the commitment to this romanticized view is why “U.S. archaeology doesn’t permit pre-Colombian states north of Mexico.”

At any rate, here are some more interesting features of Chacoan culture:

Roads. Ancient roads, sometimes to "nowhere," have been found around the area and they all lead back to Chaco. These roads have been documented using airborne Light Detection and Ranging (LIDAR) technology.

A. Cuadra/Science/Bureau of Land Management

A. Cuadra/Science/Bureau of Land Management

There's a "Great Road North" that goes straight into another canyon, called Kutz Canyon, but there's nothing there and nothing along the way. What's curious is that ancient Chacoans didn't have horses, wheels, or Teslas. So why did they have roads — which, by the way, were an incredible feat of engineering, highly technical and well-kept, and not used for any discernible purpose (no campsites were ever found along them, for example). These roads are generally straight and run straight up cliffs if they need to.

Here's one conjecture: some people think they were used for trade but were sacred, so you could walk on them but could not camp along them. Others think they were built as public works projects near the beginning of the decline of Chacoan Culture, a last "push" to keep the common civilians happy, perhaps not unlike many contemporary public works projects.

Here's another conjecture: archaeologists estimate that walking along a Chacoan road from A to B reduced caloric expenditures by 38%; it was more efficient, from an energy perspective, to walk along a Chacoan road than along the desert bed. And a 38% reduction in caloric expenditure is a tremendous boon in calorie scarce environments like ancient New Mexico.

No defenses. For a long time, there was no "warrior" class at Chaco, no gates, no forts, no citadels, etc. until right before it fell (~13th century). Yet there were incredible riches there, including: “Exotic parrots (Scarlet Macaws); chocolate from the Gulf of Mexico or Mexico's pacific coast; oyster shells from the bays of north Guaymas, Mexico; copper bells from Zacatecas; pottery from far west (Arizona); Mimbres pottery from what southern New Mexico; pipestone from the Dakotas and Alberta, Canada; and heishe shells from California coast and Texan coast.” This list was taken from David Stuart’s Anasazi America (p. 137).

Scarlet Macaw fossil (KNAU/Earth Notes).

Scarlet Macaw fossil (KNAU/Earth Notes).

To put that in perspective, I lived in the area some ~10 centuries later and, uh, the closest thing I've ever seen to a Scarlet Macaw is Pierce Randall’s pet cockatoo. I also lock my door (during the day and at night!).

Ancient astronomy. The walls of many great houses are built according to astronomical observations -- alignments that would have required intergenerational astronomical knowledge given the sheer scale and accuracy observed: "buildings like Chetro Ketl and Pueblo Bonito are oriented to face the direction of the rising and setting moon. When the moon reaches its lunar standstill (which takes place once every 18.6 years) it is framed perfectly by the doorways ... twelve of the major buildings not only align with solar, lunar, equinox, and solstice cycles, but also interrelate to each other, built in “symmetrically organized designs” on axes of major and minor lunar standstills.”

Anna Sofaer goes as far as to call Chacoan buildings “cosmological expression through architecture.”

Astronomical alignment in Chaco (Pinterest).

Astronomical alignment in Chaco (Pinterest).

There are many other curiosities at Chaco Canyon. I'll leave you with some of my questions:

(1) Why Chaco Canyon? Just to build a smaller great house (around 400 rooms), 26,000 trees had to be imported by foot from over 30 to 50 miles away (mostly west, the Chuska Mountains). There were lots of other places to build, places with water and trees, etc. nearby. Yet Chacoans chose Chaco.

(2) Why did Chacoan society collapsed dramatically? These buildings were boarded up and formally abandoned within a generation. Some answers to this question are more controversial than others.