The Mustangs, who will compete in Class 4A, are unique in that they don't have a pool and will host no meets. They practice at a nearby recreation center. Mullen will continue to swim in the 5A-based Centennial League. In 2021 in the new Season D, there will be seven duals and a league meet in the regular season. The 4A championship meet will be June 25. The first Colorado championship was officially sanctioned in 1959 and the field was switched to two classifications in 1991.