Having spent a good portion of my life prior to the Big Death living in Thunder Mountain, I actually have a fairly strong knowledge of its history. Thunder Mountain was originally the North American Air Defense Command (NORAD) military super complex headquarters located inside Cheyenne Mountain, Colorado.

In 1956, General Earle E. Partridge, Commander in Chief of the Continental Air Defense Command, determined that the United States Department of Defense required a new underground combat operations center. This new combat center needed to be distant from other prime targets and strong enough to withstand a thermonuclear shock. To administer this new command center and the entire North American air defense network, the North American Aerospace Defense Command (NORAD) was established.

Construction for the Combat Operations Center (COC) started in May 1961, and it went fully operational February 6, 1966 after a total building cost of $142.4 million. The original COC ultimately evolved into what was the Cheyenne Mountain Operations Center (CMOC). There were six main centers inside Cheyenne Mountain: Command Center, Battle Management Center, Missile Warning Center, Space Control Center, Combined Intelligence Watch Center, and Systems Center. CMOC's main mission objectives were to provide advance warning of ballistic missile or air attacks against North America, support the North American air sovereignty, and as needed acted as the focal point for air defense operations to counter enemy air attack. Luckily, it was built to be self-sustaining, capable of providing its own power, water, air, and food for long periods of time, or we would not have survived.