The Cheyenne Mountain Complex is a hardened underground military installation located inside Cheyenne Mountain in El Paso County, Colorado. Operated by the United States Department of Defense, it serves as the alternate command center for NORAD (North American Aerospace Defense Command) and USNORTHCOM (United States Northern Command). The facility was designed to withstand nuclear attacks and electromagnetic pulses, featuring massive blast doors and extensive underground infrastructure.
It continues to play a critical role in national defense operations and aerospace warning systems.