The Rams, powered by 24 first-half points and a flurry of turnovers, rolled over the Rebels 33-11 in Fort Collins, Colo., last Saturday.
McElwain says the challenge facing his young team now is avoiding the so-called "one-hit wonder" tag.
The Rams' goal of posting back-to-back wins faces a tough test in Saturday's matchup with Boise State.
The Broncos (8-2, 5-1 Mountain West) are in a tie for first place in the conference and are playing their last game at home this season.
Colorado State (3-7, 2-4) will be making its first trip to Bronco Stadium.