Cory Lewis added 12 points for the Rams (12-3, 2-1 Mountain West Conference).
Colorado State led 37-27 at the break and opened the second half with a 15-3 run to build an insurmountable 52-30 lead as Utah dropped its fifth straight.
Utes leading scorer Luke Nevill scored 10 points and added five rebounds.
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.