Most of the pre-1990 members were soon unhappy in a 16-team league. The conference now ranged from Hawaii to Oklahoma, spanning five time zones and , making travel costs a major concern. In 1999, the conference split largely along pre-1990 and post-1990 lines. Seven of the pre-1990 members—Air Force, BYU, Colorado State, New Mexico, San Diego State, Utah, and Wyoming—joined with newcomer UNLV to form the Mountain West Conference (MW).