After his sophomore season he transferred to the University of Colorado, playing until he was declared ineligible when the school was placed on probation by the NCAA in 1962.
Frank began his 15-year CFL career with the BC Lions in 1962 and was a part of the 1963 Grey Cup.
Because he still was under contract in the Canadian Football League, the Cowboys had to additionally trade running back Amos Bullocks to the BC Lions in exchange for Frank's playing rights.
[4] To complicate matters further, he signed a contract with the San Diego Chargers of the American Football League, who selected him in the 24th round (186th overall) of the 1963 AFL Draft.
The deal was eventually voided by American Football League commissioner Joe Foss.