During the first year of classes (1932-1933), Boise Junior College students picked the Bronco mascot because it represented the wild horses that roamed the Owyhees. In 1935 and 1936 the student body constructed paper and wooden broncos, nicknamed Elmer. The mascot was paraded downtown and set on fire before each homecoming game, and “From his ashes rises the spirit of new conquests and victories.”
Throughout the 1960s various live animal horses represented the Broncos. The first horse was Spyieche, a white Appaloosa stallion seen in the 1966 yearbook. After other horses were dedicated mascots, President John Barnes recommended the Associated Student Body president and College Union Director encourage the students to create a costumed mascot similar to the Idaho State Bengal.
The first costumed mascot, named Buster Bronco, appeared in Fall 1974. The first mention of his appearance comes from a letter dated October 15, 1974 from Dr. Barnes to Mr. Andy Reynolds, congratulating Andy on a great performance as Buster Bronco at the Idaho State vs. Boise State football game (October 12). Barnes mentioned that Andy’s performance was much better than before, suggesting the first act might have been the football game versus University of Nevada, Reno on October 5th. The Idaho Statesman and Arbiter newspapers make no mention of mascots for any games in October 1974.
In the 1990s, the cheerleaders introduced a second, and female, Buster Bronco. In the late 1990s, the live horse Bronco returned to football games, a tradition that continues into the 2010s. In 2002, Athletics adopted an athletics-specific Bronco logo, which lasted until 2012 when the entire University transition to a unified brand.
Sources:
Boise College: An Idea Grows by Eugene Chaffee
The Broncos: A History of Boise State University Athletics, 1932-1994 by Pat Ourada
Patricia Ourada Collection on Bronco Sports, MSS 132 Box 1 Folder 78.
University Records, RG 5.3, President John Barnes