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
Pennsylvania Route 51 Pennsylvania Route 51 Pennsylvania Route 51 (PA 51) is a major state highway in Western Pennsylvania. It runs for from Uniontown to the Ohio state line near Darlington, where it connects with Ohio State Route 14. Route 51 is the termination point for Pennsylvania Route 43, Pennsylvania Route 48 and Pennsylvania Route 88. Century III Mall is located on this road in West Mifflin. The Route is a major connection from Uniontown and the rest of Fayette County to Pittsburgh. The highway is four-lane highway south of Pittsburgh as it passes through Pittsburgh's South Hills, but narrows to a two-lane