Sector 4

Sector 4 is a Cold War-era codename for a remote detachment of the Edwards Air Force Base built on the dry lake bed of Groom Lake, Nevada. It was primarily used by the US government for the development and flight-testing of top secret aerospace projects which may have led to the F-117 Stealth Bomber, as well as, the U2, and the SR-71 reconnaissance planes. The CIA officially acknowledged the existence of the base in 1999. Sector 4 is home to the world's largest purpose-built runway, a lot of nondescript hangars and buildings, a baseball field, and a larger subterranean complex below.

Basis
Sector 4 is named in reference to S-4, the purported employment site of alleged UFO researcher Bob Lazar. Sector 4 is the Area 51 of this timeline.