DOLORES, Colo. — The dusty documentation of the Anasazi Indians a thousand years ago, from their pit houses and kivas to the observatories from which they charted the heavens, lies thick in the ground near here at Canyons of the Ancients National Monument.
Or so archaeologists believe. Less than a fifth of the park has been surveyed for artifacts because of limited federal money.
Much more definite is that a giant new project to drill for carbon dioxide is gathering steam on the park’s eastern flank. Miles of green pipe snake along the roadways, as trucks ply the dirt roads from a big gas compressor station. About 80 percent of the monument’s 164,000 acres is leased for energy development.
The consequences of energy exploration for wildlife and air quality have long been contentious in unspoiled corners of the West. But now with the urgent push for even more energy, there are new worries that history and prehistory — much of it still unexplored or unknown — could be lost.
At Nine Mile Canyon in central Utah, truck exhaust on a road to the gas fields is posing a threat, environmentalists and Indian tribes say, to 2,000 years of rock art and imagery. In Montana, a coal-fired power plant has been proposed near Great Falls on one of the last wild sections of the Lewis and Clark trail. In New Mexico, a mining company has proposed reopening a uranium mine on Mount Taylor, a national forest site sacred to numerous Indian tribes.
“We’re caught in the middle between traditional culture and archaeological research and the valid existing rights of the oil and gas leaseholders,” said LouAnn Jacobson, an archaeologist by training and the manager of both the Canyons of the Ancients National Monument and the Anasazi Heritage Center here in the four-corners area, where Utah, Colorado, Arizona and New Mexico touch.
Nationally, only about 20 percent of the 193-million-acre national forest system has been surveyed for historical or cultural content, according to a recent report by the National Trust for Historic Preservation. At the federal Bureau of Land Management, which oversees 261 million acres, including the monument here, the figure is only 3 percent.
Heightened awareness of the risk to historic sites has been fueled in part by the growing number of retirees like John Gwin who have flocked to retreats like Durango and Pagosa Springs in Colorado. Mr. Gwin, a burley former F.B.I. agent who has dedicated his retirement to the study and stewardship of the Anasazi landscape, said the region’s mix of ancient past and verdant nature was unmatched anywhere in his travels.
“I enjoy being out there, being quiet and appreciating the people who lived there 1,000 years ago — imagining what Chimney Rock meant to them,” said Mr. Gwin, who leads tours as an unpaid volunteer for the federal Forest Service at the Chimney Rock Archaeological Area, about an hour east of here.
But population growth has also brought people who are not so reverent. Instances of vandalism and illegal raids for relics — as more footprints are found leading out into once-silent Indian mounds — have risen sharply in the last few years, though few offenders are caught.
Federal land managers, tribal leaders and archaeologists call it piling on. Energy companies build roads for access to their drill pads. But then expanding populations, many of them riding off-road vehicles, use those roads for exploration or exploitation. What was once remote becomes less so, and harder than ever to defend for future generations.
“Multiple use worked for a while, but now the uses are in the same place,” said Terry Morgart, a legal researcher for the Hopi tribe in Arizona. “You can’t have recreation, cultural resources, energy development and cell towers all on the same spot. I think the agencies are aware of these conflicts, but because they’re stuck with these archaic laws, they’re between a rock and a hard place.”
Indian leaders, who link modern tribal populations in the Southwest to the ancestral Anasazi, have mounted a campaign to stop the local exploration for carbon dioxide, which would be used to help rejuvenate old oil fields that are now stirring to life in Texas and elsewhere as oil prices soar.
“Fencing dozens of sites for the facilitation of energy development is not what we had in mind when we supported the designation of the monument,” said Leigh J. Kuwanwisiwma, the director of the Hopi Cultural Preservation Office, in a letter in April to federal agencies.