Erickson was introduced as the head coach of the Division I-A Wyoming Cowboys on December 2, 1985. His four-year contract included a base annual salary of $60,000 plus $20,000 from radio and television, and the rent-free use of a home in Laramie. The Cowboys had just concluded 3–8 season in 1985, tied for seventh in the nine-team WAC. He installed his "Air Express" form of the spread offense and led the Cowboys to 3–1 start in September, with road wins at Air Force and Wisconsin. Wyoming finished at 6–6 season in 1986, tied for fourth in the WAC with a 4–4 record. He left Wyoming without notice after accepting the head coaching job at Washington State in early January.