North American Aerospace Defense Command, known until March 1981 as the North American Air Defense Command, is a combined organization of the United States and Canada that provides aerospace warning, air sovereignty, and protection for Canada and the continental United States.
The 25-ton North blast door in the Cheyenne Mountain nuclear bunker is the main entrance to another blast door in the background, beyond which the side tunnel branches into access tunnels to the main chambers.
A 1955 Sears ad with the misprinted telephone number that led to the NORAD Tracks Santa Program. NORAD Tracks Santa follows Santa Claus' Christmas Eve journey around the world. The service has expanded to various internet platforms and can be accessed seasonally by phone at: 1-877-HI-NORAD (multilingual)