Colorado State has three major rivalries. The Rams' football team plays the University of Colorado, often at Invesco Field at Mile High in Denver, in a game called the "Rocky Mountain Showdown." Within the Mountain West, Colorado State has a big rivalry with Air Force. The winner of the CSU-Air Force football game receives the Ram-Falcon Trophy. Colorado State also has a conference rivalry with Wyoming (the Border War), with the winner of the annual football game receiving the Bronze Boot. Played since 1899, the CSU-Wyoming rivalry is the second oldest interstate rivalry west of the Mississippi, behind only the "Border Showdown" (formerly "Border War") of Missouri and Kansas and just ahead of the "Red River Rivalry" (formerly "Red River Shootout") of Texas and Oklahoma played since 1900.