Rocky Mountain Showdown

The Rocky Mountain Showdown is the name given to the Colorado–Colorado State football rivalry. It is an American college football rivalry between the Colorado Buffaloes football team of the University of Colorado and Colorado State Rams football team of Colorado State University. The winner of the game receives the Centennial Cup. It began in 1893 and was played annually from 1899 to 1958, except for 1901, 1905, and 1943–44. It was revived in 1983 and played periodically until it was cemented as an annual rivalry in 1995.

Since 1998, the game has usually been played in Denver, Colorado, at Mile High Stadium and its replacement, Broncos Stadium at Mile High, although the 2004, 2005 and 2009 games were played at Folsom Field in Boulder. Broncos Stadium is considered neutral ground for both teams and has a greater capacity than either university's home stadium (Folsom Field and Canvas Stadium). Since the annual game was renewed in 1995, it has been played only once at Colorado State, in 1996 at the Rams' former home of Hughes Stadium.

In August 2009, both universities agreed to extend the Showdown until 2020, with the 2010–19 games all to be played at Broncos Stadium. The game was played in Boulder as planned in 2009, and the series will return to CSU's new stadium in Fort Collins in 2020. In 2015, Colorado athletic director Rick George stated that he wanted to return the series to campus sites, but that it was not in Colorado's best interest to extend the series. Since the ending of the annual Utah/Utah State game in 2015, the Rocky Mountain Showdown is currently the oldest rivalry in the Football Bowl Subdivision (FBS) of NCAA Division I college football, between two public universities, in the same state, that have a game named "University of _ vs. _ State University."