Jim Bertelsen played halfback for the University of Texas at Austin from 1969–1971. He was a highly regarded Wisconsin high school football player, playing for the Hudson High School Raiders. He helped lead the Texas Longhorns to a National Championship in 1969, playing halfback in the famed Wishbone formation, alongside James Street, Steve Worster and Ted Koy. Jim Bertlesen was the team's lead ground gainer in 1971. In his career at Texas from 1969–1971, he rushed for 2,510 yards averaging 6.1 yards a carry and 33 touchdowns. He also had 9-100 yard rushing games. After his career with the Los Angeles Rams, Bertelsen returned to the Austin area.