The Nellis Air Force Base Complex is the southern Nevada military region of federal facilities and lands, e.g., currently and formerly used for military and associated testing and training such as Atomic Energy Commission atmospheric nuclear detonations of the Cold War. The largest land area of the complex is the Nevada Test and Training Range, and numerous Formerly Used Defense Sites remain federal lands of the complex. Most of the facilities are controlled by the United States Air Force and/or the Bureau of Land Management, and many of the controlling units are based at Creech and Nellis Air Force Bases (e.g., 98th SRSS for NTTR's southern range). Initiated by a 1939 military reconnaissance for a bombing range, federal acquisition began in 1940, and McCarren Field became the World War II training area's 1st of 3 Nevada World War II Army Airfields (cf. Indian Springs & Tonopah) and 10 auxiliary fields. The area's first military unit was initially headquartered in the Las Vegas Federal Building while the WWII Las Vegas Army Airfield buildings were constructed.
