An observatory at an altitude of 2788 m in the Sacramento Mountains near Sunspot, New Mexico. It houses a 3.5-m reflector opened in 1994; a 2.5-m reflector built for the Sloan Digital Sky Survey which began operation in 1998; and a 1-m reflector owned by New Mexico State University. The observatory is owned by the Astrophysical Research Consortium (ARC), whose members are the University of Washington, New Mexico State University, the University of Colorado, Johns Hopkins University, the University of Virginia, and Georgia State University; New Mexico State University also operates the observatory for the Consortium.

http://www.apo.nmsu.edu/ Official observatory website.