1961 Press Photo Blast doors inside NORAD's Combat Operations Center, CO

Thirty-ton swingers - Gigantic blast door swing open to let the underground people from the North American Air Defense Command's Combat Operations Center, deep inside Cheyenne Mountain near Colorado Springs, head for home. The finely balanced 30-ton steel doors are operated electronically and can be closed in 30 seconds. Located 50 feet apart and encased in 17-foot-thick concrete collars, they are another survival precaution employed in the mountain complex to guard the people who would direct aerospace defense of North American in event of an enemy attack. US Air Force.

Photo is dated 1961.

Photo measures 10 x 8.25 inches.