An aerial photo shows ancient linear roads that led to Pueblo Alto in Chaco Culture National Historical Park.
About 1000 years ago, indigenous people built an elaborate network of great houses, kivas, and grand roads centered on Chaco Canyon, in the middle of the San Juan Basin of present-day New Mexico. Today, the region is one of the nation’s most productive oil and gas basins. It is also the setting of a collision between burgeoning energy development and archaeology, as new discoveries reveal the importance of the larger landscape in understanding Chacoan society.
Taking advantage of advances in drilling technology, more than 4000 new wells will be developed in the area in the coming years, predicts the Bureau of Land Management (BLM), which manages development of federal mineral resources. Late last month, a federal judge issued a decision that may encourage the sale of oil and gas leases and eventual drilling near the Chaco Culture National Historical Park and known ancient roads. As a coalition of environmental and tribal groups mulls an appeal, they also await a new management plan from BLM, due as early as next month. With President Donald Trump’s administration pushing for more oil and gas development on public lands, they worry the new plan may favor development at the expense of cultural and environmental protection.
Meanwhile, advances in remote sensing are revealing hundreds of previously unknown roads between Puebloan sites. As companies scrape well pads and access roads from the high desert scrub, archaeologists fear they will erase ancient roads before they have been fully studied—or even detected. “This real intense development that they’re talking about essentially transforms the landscape into an industrial park,” said John Roney, an independent cultural consultant based in Albuquerque, New Mexico, who formerly worked for BLM and conducted the first aerial survey of Chaco roads.
Although the park encompasses the largest pueblo, hundreds of smaller sites dot a 100,000-square-kilometer area surrounding the point where Arizona, Colorado, New Mexico, and Utah meet. Old aerial photos had traced roads extending from some sites. But a 2017 paper in Advances in Archaeological Practice revealed previously unknown roads.
For this project, Anna Sofaer, an archaeo-astronomer who heads the nonprofit Solstice Project in Santa Fe, collaborated with Richard Friedman and Robert Weiner, who specialize in lidar, a technology that uses