An observatory at an altitude of 1740 m on Mount Wilson in the San Gabriel Mountains about 30 km northwest of Los Angeles, founded by G. E. Hale in 1904 for solar observation. Mount Wilson Observatory is owned by the Carnegie Institution for Science and has been operated since 1991 by the Mount Wilson Institute. Its main instrument is the 100-inch (2.5-m) Hooker Telescope, opened in 1917. There is also a 60-inch (1.5-m) reflector (1908). Two tower telescopes for solar observation, 18 m and 46 m high, were opened in 1907 and 1909; they have been operated since 1986 by the University of Southern California and the University of California at Los Angeles, respectively. Mount Wilson is also the site of the Infrared Spatial Interferometer (ISI) consisting of three movable 1.65-m mirrors, operated by the University of California at Berkeley, and of the CHARA Array.

http://www.mtwilson.edu/ Official observatory website.