ALBUQUERQUE, NEW MEXICO—In response to the threat of gas and oil development to more than one million acres surrounding Chaco Culture National Historical Park, the Society for American Archaeology, New Mexico Archaeological Council, Chaco Alliance, WildEarth Guardians, the San Juan Citizens Alliance, and other concerned citizens petitioned the Bureau of Land Management to designate a Greater Chaco Landscape Area of Critical Environmental Concern. The Great North Road and several Chacoan Great House Communities are some of the significant archaeological sites that are at risk. Drilling and other procedures can trigger small earthquakes that could cause structure collapse. Development would also impact Chaco’s notable dark sky, and the emptiness and silence of the surrounding landscape.