Area 51 request filed in 2005, the CIA publicly acknowledged the existence of the base for the first time, declassifying documents detailing the history and purpose of Area 51. Area 51 is located in the southern portion of Nevada in the western United States, north-northwest of Las Vegas. Situated at its center, on the southern shore of Groom Lake, is a large military airfield. The site was acquired by the United States Air Force in 1955, primarily for the flight testing of the Lockheed U-2 aircraft. The area around Area 51, including the small town of Rachel on the "Extraterrestrial Highway", is
Area 51 aerospace magazine "The Space Review" titled "Astronauts and Area 51: the Skylab Incident". The article was based on a memo written in 1974 to CIA director William Colby by an unknown CIA official. The memo reported that astronauts on board Skylab 4 had, as part of a larger program, inadvertently photographed a location of which the memo said: Although the name of the location was obscured, the context led Day to believe that the subject was Groom Lake. As Day noted: The memo details debate between federal agencies regarding whether the images should be classified, with Department of Defense agencies