Simplify the following text for a Grade 11 native English-speaking person.
Original: Its main technical facility has been the Cheyenne Mountain Operations Center in Colorado , and for this reason NORAD is sometimes unofficially referred to as Cheyenne Mountain .
Simplified: Its main technical facility has been the Cheyenne Mountain Directorate , formerly Cheyenne Mountain Operations Center , of the Cheyenne Mtn . Air Force Station , Colorado ; and for this reason NORAD is sometimes referred to as Cheyenne Mountain .