	In his rookie PRCA season, 1976, Cooper won the organization's tie-down roping championship and led the event in average earnings at the National Finals Rodeo (NFR). He broke the record for the most prize money won by a rookie cowboy, and earned the PRCA's Rookie of the Year award. In 1977, Cooper was the third-leading earner at the NFR's roping event. At the 1978 Cheyenne Frontier Days rodeo, he led all cowboys in prize money won, and his calf-roping winnings were the largest recorded in any non-NFR event at the time. After breaking one of his wrists the previous year, Cooper won his second calf roping season championship in 1980, and had a third-place NFR average earnings finish in the discipline. The following year, he earned his second straight season calf roping title. However, he narrowly lost out on the PRCA's All-Around Cowboy season championship to his cousin, Jimmie Cooper, who earned $47.60 more in prize money than he did during 1981.