Prior to his tenure with the 49ers, Christianson also served on University of Michigan Head Coach Jim Harbaugh's staff at the University of San Diego (USD) where the Toreros of the Pioneer Football League won a Division I-AA Mid-Major National title in 2006.
Christianson coached the offensive line in 2002-2003 as a member of Jon Gruden's staff and the Tampa Bay Buccaneers,[2] winning Super Bowl XXXVII (37).
In 1995, he spent one season with the Lewis & Clark College Pioneers (NAIA DivII) as the recruiting coordinator and tight-ends/running backs coach.
Dunn, who played at PSU from 1997 to 2000, rushed for more than 6,000 yards[3] as a Viking, was a first-team All-American and is a member of the Portland State Athletics Hall of Fame.
[7][8] He coordinated and helped develop large football technology projects at the Oakland Raiders, the University of Nebraska and the San Francisco 49ers to name just a few.
[11] He also coached USD starting tight end Chris Ramsey to a 2nd Team Mid-Major All-American honors.
[13] Working closely with Tom Rathman, Christianson played a major role in 2011 in the development of the 49ers rushing attack[14] and in mentoring veteran player Frank Gore to his 5th 1,000 yard season.