Rainbow Warriors coach Norm Chow also announced Friday that Idaho State assistant Don Bailey has been hired as offensive coordinator.
Mason took over at SMU two games into last season after coach June Jones resigned. The Mustangs went 1-9 under Mason.
Bailey had been offensive coordinator and quarterback coach at Idaho State the last four seasons. Idaho State led the FCS in passing offense (348.1 yards per game) and ranked second in total offense (562.0 ypg) last year.