The Nevada Test and Training Range (NTTR) is a training facility of the United States Air Force located in the desert of southern Nevada in the United States. It is the largest of its kind in the US, 4687 sq. mi. (12139 km²) and is operated by the USAF Warfare Center's 98th Range Wing. The NTTR was renamed from the Nellis Air Force Range (NAFR) in 2001.
NTTR borders (on three sides) the Department of Energy's Nevada Test Site; between them the two complexes control much of the land in southern Nevada. NTTR is operated from Nellis Air Force Base near Las Vegas. The National Wildhorse Management Area is entirely enclosed inside the NTTR, and much of the eastern section of the NTTR overlaps with the Desert National Wildlife Refuge.
The terrain enclosed by the range is characterized by numerous small ranges of mountains, with the area between consisting of desert, including many small endorheic lakes. One of these, Groom Dry Lake (located near the northeast border of NTTR) is reportedly the location of the air force's secret test facility, popularly known as Area 51.
At least once per year NTTR hosts RED FLAG, a combined NATO simulated air warfare exercise. NTTR is also the location of Green Flag, a similar exercise emphasising the electronic aspects of airborne warfare.