The Colorado State–Wyoming football rivalry is an American college footballrivalry between the Colorado State Rams football team of Colorado State University and Wyoming Cowboys football team of the University of Wyoming. The Bronze Boot is awarded to the winner of the game. This rivalry has evolved into one of the most bitterly contested in college football. The teams have waged the "Border War" more than one hundred times since the schools began playing in 1899, playing every year except 1901, 1902, 1906, 1907, 1918, 1924, 1926, 1927, 1928, 1943, 1944, and 1945. In fact, this is one of the oldest interstate rivalries west of the Mississippi River, and the oldest west of the Missouri. The series is the oldest rivalry for both schools and the "Border War" has been played in three different centuries.
In 1968, the ROTC detachments of the respective schools initiated the Bronze Boot, a traveling trophy awarded to the winner of the “Border War” each year. The boot was worn in the Vietnam War by Cpt. Dan J. Romero, an Adams State College graduate and Army ROTC instructor at CSU between 1967 and 1969. Each year leading up to the Colorado State–Wyoming game, the game ball is carried in a running shuttle relay by the ROTC detachment of the visiting team down US 287 to the Wyoming-Colorado state border, where the home team's ROTC detachment receives it and runs the game ball to the stadium hosting the game. The trophy is guarded by the ROTC unit of the past year's winning school during the game.