After graduating from Jesuit High School, Pettibone received a scholarship to the University of Oklahoma in Norman, where he played halfback for the Sooners under head coach Bud Wilkinson.
Pettibone recruited running back Billy Sims, the Heisman Trophy winner in 1978 after rushing for 1,782 yards.
Pettibone's first head coaching position was in 1985 at Northern Illinois University in the Mid-American Conference (MAC) and he led the Huskies for six seasons, the last five as an independent.
Northern Illinois recorded its first-ever victory over a ranked team (top 25) in 1990 when it routed #24 Fresno State 73–18 on October 6 in DeKalb.
After the 1990 season, Pettibone left NIU in early December for the Pacific-10 Conference at Oregon State University in Corvallis, replacing Dave Kragthorpe.
Oregon State finished second in the nation in rushing in 1993, and Pettibone was named co-runner-up for the Division I-A Coach of the Year honors by Sports Illustrated.
[8] In addition to his responsibilities with Sooners Helping Sooners he also has maintains a personal football evaluation service for high school and junior college athletes to help them determine what level their playing ability falls under, and how to navigate the college recruiting process.