The Denver Air Defense Sector was a NORAD geographic area designated during the Cold War in the Zone of Interior (ZI) for both air defense and air traffic control, as well as the name of the planned military unit for conducting radar surveillance and fighter-interceptor operations in the sector area. The Denver ADS spanned the entire state of Colorado, nearly all of Utah, most of Wyoming and western Nebraska, and small parts of Kansas, Oklahoma, New Mexico, Arizona, and Nevada. Targets in the sector included the military/industrial facilities and urban civilian populations of the metropolitan areas at Salt Lake City, Cheyenne, Denver, and Colorado Springs—the Colorado underground ICBM construction began in tbd. (Omaha and Wichita military/industrial complexes were in the Sioux City sector)