Marilyn was a three-time U.S. national champion during her career. In the 1969 season, she finished runner-up in the final five giant slalom races and won the World Cup season title. Cochran was the only American alpine racer with a World Cup season title until 1980, when Phil Mahre won the combined. She won the bronze medal in the combined at the 1970 World Championships in Val Gardena, Italy. Sister Barbara was fourth in that competition, but won a silver in the slalom, where Marilyn was sixth.