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
Indiana State Road 51 Indiana State Road 51 State Road 51 in the U.S. state of Indiana is a north–south route on the state highway system in northwest Indiana. It consists of a route long from a point on U.S. Route 30 (Lincoln Highway) east of Merrillville and west of Valparaiso, north to U.S. Route 20 in Gary. Immediately north of US 30, the highway is signed as the Adam Benjamin Highway. SR 51 travels north on Lake Park Avenue from US 30, crossing Old Lincoln Highway and the mainline of the Canadian National Railway in the former town of Ainsworth before turning east