Area 51 the base extends further east. After leaving the restricted area, Groom Lake Road descends eastward to the floor of the Tikaboo Valley, passing the dirt-road entrances to several small ranches, before converging with State Route 375, the "Extraterrestrial Highway", south of Rachel. Area 51 shares a border with the Yucca Flat region of the Nevada Test Site, the location of 739 of the 928 nuclear tests conducted by the United States Department of Energy at NTS. The Yucca Mountain nuclear waste repository is southwest of Groom Lake. Groom Lake is a salt flat in Nevada used for runways of the
Area 51 plunging the aircraft into the sagebrush. Area 51 pilots called it "The Hook". For crosswind landings two unpaved airstrips (runways 9/27 and 03/21) were marked on the dry lakebed. By August 1961, construction of the essential facilities was completed (3 surplus Navy hangars were erected on the base's north side—hangars 4, 5, and 6.) A fourth, Hangar 7, was new construction. The original U-2 hangars were converted to maintenance and machine shops. Facilities in the main cantonment area included workshops and buildings for storage and administration, a commissary, control tower, fire station, and housing. The Navy also contributed more than