Barnum moved up to the Division I level in 1991 as assistant offensive line coach and freshman offensive coordinator at Cornell, where he would remain for two seasons under Jim Hofher. In 1993, Barnum returned to the Division II level as offensive line coach and run game coordinator at American International College. Barnum then coached at the Division III level, at Coast Guard as offensive line coach and assistant head coach from 1994 to 1997. After his stint at Coast Guard, Barnum returned to the Division I level at Idaho State and started as offensive line coach in 1998 under Tom Walsh.
Barnum
Tom Walsh