The Tonopah Test Range (TTR, also designated as Area 52) is a highly classified, restricted military installation of the United States Department of Defense, and United States Department of Energy nuclear weapons test range (stockpile stewardship) located about 30 miles (48 km) southeast of Tonopah, Nevada. It is part of the northern fringe of the Nellis Range, measuring 625 sq mi (1,620 km2). Tonopah Test Range is located about 70 miles (110 km) northwest of Groom Lake, the home of the Area 51 facility.