Cheyenne Mountain is a triple-peaked mountain in El Paso County, Colorado, southwest of downtown Colorado Springs. The mountain serves as a host for military, communications, recreational, and residential functions.
The Cheyenne Mountain Complex, an operations center for the North American Aerospace Defense Command, was built during the Cold War to monitor North American airspace for missile launches and Soviet military aircraft. Built deep within granite, it was designed to withstand the impact and fallout from a nuclear bomb.
During the beginning of the War of 1996, President Thomas Whitmore's Vice President, the Cabinet, the Joint Chiefs of Staff, their advisers and families were evacuated from Washington, D.C. to Cheyenne. Following the U.S. military's failed counterattack against the aliens, the mountain complex came under attack by swarms of alien fighters which they blasted through and destroyed the complex, killing everyone. Shortly thereafter, Peterson Air Force Base came under attack.
Two decades since the invasion, the Cheyenne complex was rebuilt and refortified. During the sudden outbreak of the War of 2016, President Elizabeth Lanford and her Cabinet were immediately evacuated to the Cheyenne bunker. When the aliens detonated an electromagnetic pulse across Earth, Cheyenne lost all communications with the Earth Space Defense. Soon afterwards, the bunker came under attack by an alien strike force which they breached through and killed everyone, except for Lanford, who was captured instead.