Cloudcroft Observatory, in New Mexico's Lincoln National Forest near Cloudcroft, began as a Cold War U.S. Air Force research site selected in 1961 and built in 1962 as the Cloudcroft Electro-Optical Research Facility. It developed electronic methods for detecting satellites beyond earlier photographic systems, and its main Electro-Optical Surveillance Telescope began operating in 1964. Space object identification research continued there through 1975, followed by later Air Force and guest research use. Deactivated in 1982, the facility returned to active astronomy in 1995 as NASA's Orbital Debris Observatory, where a liquid-mirror telescope operated from 1996 to 2001. By 2013, private ownership continued the site's long role in tracking objects in space.