What underground nuclear bunker near Blue Ridge Summit, Pennsylvania known as "underground Pentagon" became operational in 1966?
Raven Rock Mountain Complex The Raven Rock Mountain Complex (RRMC) is an American military installation with an underground nuclear bunker near Blue Ridge Summit, Pennsylvania, at Raven Rock Mountain that has been called an "underground Pentagon." The bunker has emergency operations centers for the United States Army, Navy, and Air Force. Along with Mount Weather Emergency Operations Center in Virginia and the Cheyenne Mountain Complex in Colorado, it formed the core bunker complexes for the US Continuity of Government plan during the Cold War to survive a nuclear attack.
Cannikin Cannikin was an underground nuclear weapons test performed on November 6, 1971, on Amchitka island, Alaska, by the United States Atomic Energy Commission. The experiment, part of the Operation Grommet nuclear test series, tested the warhead design for the LIM-49 Spartan anti-ballistic missile. With an explosive yield of almost 5-megatons TNT equivalent, the test was the largest underground explosion ever detonated by the United States.