Complex sentence: On December 3,1990, he was promoted to Offensive Coordinator and his first game as OC was against Notre Dame in the 1991 Orange Bowl which Colorado won to earn their first and only NCAA Division I-A national football championship.
Split into simpler sentences: On December 3,1990, he was promoted to Offensive Coordinator. His first game as OC was against Notre Dame in the 1991 Orange Bowl which Colorado won to earn their first (and only) NCAA Division I-A national football championship.