Cheyenne Mountain Nuclear Bunker - History

History

United States defense plans in 1945 and 1947 "recommended moving ADC Headquarters from Mitchel Field to a more central location…in a protected command center … designed to withstand attack by all foreseeable weapons" (e.g., "German A-4 type" missiles). The subsequent 15,000 sq ft (1,400 m2) concrete block command post at Ent AFB, Colorado, was completed in May 1954 and supported the 1953 "The New Look" strategy dubbed "Massive retaliation": "to minimize the threat", "the major purpose of air defense was not to shoot down enemy bombers--it was to allow SAC" "to get into the air not be destroyed on the ground massive retaliation". In December 1956 the CONAD commander proposed that a bunker replace the above-ground Ent blockhouse, and Canada's NORAD bunker with a SAGE AN/FSQ-7 computer was begun in 1959.

On February 11, 1959, the JCS approved the US bunker project and assigned development to the USAF which selected the "NORAD cave" site based on RAND's recommendation (JCS site approval was March 18, 1959). After the DoD 1959 "Master Air Defense Plan" cut back on planned SAGE "Super Combat Centers" with underground solid state computers (cancelled February 1960), the NORAD command center operations were instead moved from Ent to the 1963 Chidlaw Building's partially underground "Combined Operations Center" also used by Aerospace Defense Command. Following an August 1959 Nike ABM interception of a test missile, the mission was expanded in August 1960 to "a hardened center from which CINCNORAD would supervise and direct operations against space attack as well as air attack". Built after more than 11 previous US command bunkers (e.g., 1953 Raven Rock through 1960 Ft MacArthur AADCP), Cheyenne Mountain was originally intended to provide a 70% probability of continued operation after a 5 megaton nuclear detonation 3 mi (2.6 nmi; 4.8 km) away. The bunker was instead designed for a 30 megaton blast within 1.0 nmi (1.9 km; 1.2 mi).