NORAD
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. Headquarters for NORAD and the NORAD/United States Northern Command center are located at Peterson Space Force Base in El Paso County, near Colorado Springs, Colorado. The nearby Cheyenne Mountain Complex has the Alternate Command Center. The NORAD commander and deputy commander are, respectively, a United States four-star general or equivalent and a Canadian lieutenant-general or equivalent.