Walt served a three-year apprenticeship on the Cowboys' bench behind Don Perkins and when Don retired prior to the 1969 season, Walt finally got his chance at a starting berth. That year he rushed for 818-vards and combined with Calvin Hill to form the best one-two punch in the club's history. An all-time star at Oklahoma State, he was a two-time All-Big Eight selection. Walt rushed for 730-yards as a junior and 924-yards in his senior year, including 121 against an undefeated Nebraska team and 173 against Kansas State. He played in the East-West Shrine Game and the Senior Bowl Game then was drafted by the Cowboys. He had an impressive rookie season in 1966, leading both the kickoff and punt coverage teams in tackles.