U.S. Naval Observatory

Flagstaff, Arizona. Established in 1955 a few miles west of Flagstaff, Arizona, the Flagstaff station is the US Naval Observatory’s dark-sky site for optical and near-infrared astronomy. There are presently two USNO sites in the Flagstaff area: this station and the Navy Prototype Optical Interferometer, located some 15 miles south of the city. Source: USNO.