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
Alabama State Route 51 reaches its northern terminus at Opelika. When SR 51 was formed in 1940, it covered only the route between Clayton and Midway. The highway was extended to its current southern terminus in 1957, and was extended to its current northern terminus in 1986. Alabama State Route 51 State Route 51 (SR 51) is a state highway in the southeastern and east-central parts of the U.S. state of Alabama. The southern terminus of the highway is at an intersection with U.S. Route 84 (US 84) near New Brockton. The northern terminus of the highway is at an interchange with I-85/US 29/US