History, mystery in Chaco Canyon ruins

There are 788 U.N. World Heritage sites: The Galapagos Islands of Ecuador and England’s Stonehenge pop to mind immediately. Of America’s 20 venues, most -- like Yellowstone and the Statue of Liberty -- are easily accessible destinations with well-understood histories.

By contrast, Chaco Culture National Historical Park in northwestern New Mexico is hard to reach and enigmatic. The remote canyon on the Colorado Plateau’s high desert is reachable by unpaved roads full of car-eating potholes, jaw-jarring washboard and caliche that turns to slippery soup when rain or snow falls. Here, remains of ancient buildings known as “great houses” attest to a once-flourishing civilization. Chaco was mostly abandoned by 1140, however, and its purpose is still a mystery.

“How and why did the great houses come into being?” asks Brian Fagan, emeritus professor of anthropology at UC Santa Barbara. Since whoever made these huge structures had no writing system, no firsthand explanations exist. “Did the great houses serve as vast granaries as well as community centers?” Was Chaco a “great ritual center or a marketplace, or a symbolic hub of a much larger world?”

Numerous questions have persisted ever since the ruins were discovered, probably in the late 18th century. Fagan introduces its early explorers, treasure hunters and archeologists such as Richard Wetherill, the Colorado cattle rancher who financed “a heavy mortgage” selling antiquities in the late 19th century, and George Pepper, an assistant curator from New York’s American Museum of Natural History, a young man with “absolutely no archeological experience whatsoever.”

The two “cleared rooms ... by the dozen” in Chaco’s most impressive structure, Pueblo Bonito, then used the ancient building for storage and scavenged its wooden beams for shelter. Wetherill filed a homestead claim that included three Chaco great houses, and reaped such substantial profits that government investigations halted excavations in 1901. When fieldwork resumed, this piracy and damage along with lost materials and incomplete records made understanding the “jigsaw of rooms, kivas and construction styles” all the more difficult.

Fagan begins by discussing what’s known of ancient life in the San Juan Basin, and how climate -- particularly rainfall -- is a factor in subsistence agriculture and population trends. Next, he explains how tree-ring growth patterns allow scholars to construct a relative chronology of building and remodeling in the area.

But learning when this concentration of great houses was created doesn’t explain why. There are numerous theories about Chaco, and Fagan offers interpretations to perplexing puzzles. He examines how many people might have lived and worked here, why they chose this place and eventually left, how they might have governed, conducted trade and observed religious rites, as well as why the builders also made wide, straight roads that now fade into empty desert.

Yet his conclusions can leave the reader confused. For example, why does he assume that the roads were “essentially nonutilitarian” and “never a network that connected different communities”? Why bring up a topic as startling as “human sacrificial victims,” then provide only an endnote citing an article? Why no notice of Fajada Butte’s famous spiral sun dagger petroglyph, which prompted theories about Chaco as a center for celestial observation, where the alignments of the great houses formed some sort of calendar?

So much about Chaco remains secret; perhaps it’s fitting Fagan’s account raises many questions.

Irene Wanner is the author of “Sailing to Corinth.”