1961 Press Photo Steel buildings inside Colorado mountain; Air Defense Op Center

Steel buildings roofed by several hundred feet of granite are part of ... providing protection for North American Air Defense command's underground Combat Operations Center. Built deep inside the granite caverns hollowed out within the mountain this is one of the eight three-story buildings in the complex. All the buildings are mounted on massive steel springs to further protect the electronic equipment of the Aerospace defense command post from earth-jarring nuclear blasts. Colorado.

Photo is dated 1961.

Photo measures 8 x 10.25 inches.