Into thin air

THEY lived on the edge of the world, in the red mountains of the desert Southwest, in houses with T-shaped doorways tuned to arcane celestial events. They fashioned elaborate pottery, grew corn and beans in obdurate soil, built ceremonial chambers (kivas) dedicated to sun, stars and gods. By the 11th century, they were a highly evolved, technological society. And then, suddenly, they were gone. "Farming implements were left in the fields," writes naturalist and desert ecologist Craig Childs in "House of Rain." "Ceramic vessels remained neatly stowed in their quarters; ladles rested in bowls as if people had been swept from the land by an ill and sudden wind."

Or so the story goes. As Childs explains it, no one really knows what happened to the ancestral tribes of the Southwestern canyons now lumped together as the Anasazi. Their disappearance has captivated modern explorers, professional and casual. It is a mystery pieced together from tree-ring patterns in fallen roof beams, pottery shards, human bone fragments unearthed by archeologists and hikers (one of them a Boy Scout whose flashlight fell down a hole). Any number of solutions to the mystery could be true.

In "House of Rain" (the title refers to the dwelling of an ancient god), Childs does not undertake to solve the mystery or referee among bickering archeologists. Instead, he sets out to ramble through the ancient canyons with their crumbling kivas, to linger over the pottery shards and human bones and to interview the archeologists who have devoted their lives to understanding these ancient people whose very name is in dispute. "The word 'Anasazi' was crafted by the Navajo, who in the 1800s were paid by white men to dig skeletons and pots out of the desert," Childs writes. Long thought to mean "old ones," it in fact translates as "enemy ancestors," which naturally angers the Anasazi's descendants, who include the Hopi and Zuni tribes. Midway through the book, Childs simply abandons the appellation, which, he explains, "had grown fainter with every mile I had traveled."

Childs' journey begins at Chaco Canyon, in northwestern New Mexico. From there, he treks to Utah and then south again, to the ancient northern Mexico town of Paquime (now Nuevo Casas Grandes), where a later civilization much like the Anasazi flourished. Sometimes, Childs travels with his wife and their baby son, allowing him to ruminate on the intricacies of tending to a toddler on the trail. Sometimes, he travels with friends, with whom he negotiates flash-flood channels and vaults over crevasses. It is a somberly focused, physical trip, and you learn at the outset just how precisely he will describe it. ("At the river I untied the canoe's bowline, stepped in, and swept the paddle into the water, setting a wake across a mirror of stars.")