The Cheyenne Mountain Complex is a hardened military installation located inside Cheyenne Mountain in El Paso County, Colorado. Operated by the United States Department of Defense, this facility serves as an alternate command center for NORAD and USNORTHCOM. The complex is designed to withstand nuclear attacks and electromagnetic pulses, featuring massive blast doors and reinforced structures.
It remains an active military installation, though its primary role has evolved from Cold War-era defense to modern aerospace and homeland security operations.