Cloudcroft Observatory, Astronomical observatory in Lincoln National Forest, New Mexico, US.

Cloudcroft Observatory stands in the Lincoln National Forest near Cloudcroft, New Mexico, about 23 km northeast of Alamogordo. Its main dome holds a 1.0 m Ritchey-Chrétien reflecting telescope, tested there as of April 2013. The building dates from 1962, when it was built as the Cloudcroft Electro-Optical Research Facility.

Built in 1962 as the Cloudcroft Electro-Optical Research Facility, the site was owned by the U.S. Air Force and run by the Air Force Avionics Laboratory. Its 1.22 m Newtonian telescope, the EOST, saw first light in 1964 to test electronic imaging of satellites. AFAL ran Space Object Identification work until 1975, when SAMSO took over; the facility was deactivated in 1982 and the telescope moved to Table Mountain Observatory. NASA returned from 1995 to 2002 as the NASA Orbital Debris Observatory, installing a 3.0 m liquid-mirror telescope that ran from 1996 to 2001.

The site's name followed its operators: the Air Force called it the Cloudcroft Electro-Optical Research Facility, NASA renamed it the NASA Orbital Debris Observatory from 1995 to 2002, and it now bears the name Cloudcroft Observatory, with observatory code V29. The Tzec Maun Foundation, a private astronomical organization, owns the facility today.

The mountain location requires preparation for high elevation and changing weather conditions, especially during cooler seasons. Visitors should plan ahead since access conditions can vary significantly.

The 1.22 m EOST telescope of 1964 sat on a three-axis azimuth-elevation-azimuth mount, and two small Naval sight guns in corner domes helped aim it at poorly constrained targets. The first automated detection system, FSR-2, stood in a separate building in the late 1960s and ran only one year.