Terms of the deal were not released Wednesday.
The agreement runs from the 2013-14 school year to the 2019-20 season.
CBS Sports Network will still be the hold primary rights to the conference through 2015-16, and will get first selection of football games each week during the season, excluding Boise State home games.
CBS Sports Network will hold rights to Boise State's road conference games.
In addition to Boise State home games, ESPN will get rights to up to 16 Mountain West football games and 31 men's basketball games per year.