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
Minnesota State Highway 51 The northern terminus of Highway 51 at I-694 in Arden Hills is also shared with the westbound interchange for U.S. Highway 10. From south to north, the route adjoins the campuses of Macalester College, Hamline University, University of Northwestern - Saint Paul, and Bethel University. Como Park, Zoo, and Conservatory in Saint Paul is located 7 blocks east of the junction of Highway 51 (Snelling Avenue) and Como Avenue. Eastbound Como Avenue becomes Horton Avenue. The park entrance is on Horton Avenue near Lexington Parkway. Rosedale Center and Har Mar Mall shopping centers are located on the route in Roseville.