You can generally distill the Mountain West Conference Mountain division race down to "Boise State vs. somebody." Since divisional play began out west in 2013, the Broncos have reached the conference title game five times (winning three), tied for first in the Mountain once and finished one game back three times.
The latter happened in 2021, as BSU beat Utah State and Fresno State by a combined score of 67-17, but finished a game back of USU because of a pair of home upsets and a late loss to San Diego State.