Mesa Verde trial by fire: although large parts of this national park have burned in recent years, its stunning cliff dwellings and artifacts have survived, thanks to expert management.

• Author: Wyels, Joyce Gregory

Burnished by the late afternoon sun, precise geometric forms fill a natural sandstone alcove high above the canyon floor. The sight, reminiscent of a cubist composition, dazzles onlookers--all the more so because of the realization that this niche, and others like it, once sheltered human beings. Small wonder that Colorado's Mesa Verde National Park was named the U.S.'s first UNESCO World Heritage Site, in 1978.

Mesa Verde distills the story of the people who farmed the mesa from the sixth through the thirteenth centuries while constructing increasingly sophisticated housing, culminating in the much-admired cliff dwellings. By A.D. 1300, their structures stood abandoned. If unanswered questions linger about the cliff-dwellers's choice of abode--and their abrupt departure--the mysteries only add to the allure of this vanished civilization.

The park lies at the heart of the Four Corners area, where the states of Arizona, New Mexico, Utah, and Colorado meet. A hub of Native American cultures even today, the region is sparsely populated but rich in archaeological remains.

Apart from sweeping views of mesas and canyons, and the glimpse of past centuries afforded by the well-preserved dwellings, stark scenes have greeted visitors to Mesa Verde in recent years. Skeletal black trees testify to the destructive fires that have swept across the oak, pinon pine, and juniper forests of the mesa during three of the last four summers. But the famous cliff dwellings remain unscathed by the fires, earning Mesa Verde recognition for its fire-management techniques, as well as its archaeological treasures.

Because fire can destroy archaeological sites and artifacts, park officials face a dilemma. On the one hand, they must suppress fires as quickly as possible in order to protect the ancient sites. But hazardous fuels have built up; this in turn can lead to catastrophic wildfires. "Despite everything we do, fire is a natural process, and whether we burn it under some management plan or let nature take its course, it's probably going to burn some day," says Chief Ranger Charlie Peterson, who oversees visitor protection and fire management.

On a positive note, the fires often uncover new sites. "The stuff that were been finding might not be a Cliff Palace or a Spruce Tree House," says archaeologist Gay Ives, referring to two of the most visited cliff dwellings. "But we do find new alcove sites that have never been discovered; we find mesa-top sites; we find new features that had never been recorded before. When you suppress fire for one hundred years, the trees that are dead and down cover these features. You can't see it because the duff layer can be several inches to several feet thick."

Newly uncovered sites give archaeologists a more complete picture of what Mesa Verde looked like during its period of occupancy. "It gives us a population-density study to find out how many people lived here at what time," says Ives. "It tells us time periods. There are all sorts of studies that we can learn from." One research project studies the effects of fire retardant on ancient walls and petroglyphs.

To protect Mesa Verde's resources, archaeologists work side by side with firefighters--and some eases actually serve as firefighters. "It's pretty exciting," says Julie Bell, an archaeologist who is "red-carded" as a firefighter. "The first day it's just a scramble to get as much manpower as we can out there on the line, and then it's usury the second day that we turn into archaeologists and go out with the crews." A crew, she explains, generally consists of twenty people who dig a line between burned and unburned vegetation.

"We work with the crew...