[1][2] Walberg graduated from Monta Vista High in Cupertino, California in 1974, where he was the team's Most Valuable Player in winning a league championship.

He spent two seasons at De Anza Community College, where he won two conference championships and finished as the school's all-time steals leader.

Walberg then became the head coach at Newark (Calif.) Memorial High School for five seasons (1985–89), winning one league title on two trips to the championships.

In October 2012, George Karl announced that Walberg officially joined the Nuggets' staff as an assistant coach.

[10] On July 20, 2016, Walberg returned to Clovis West High School as varsity boys' basketball head coach.