Larry Bielenberg was first introduced to sports as a student at Silverton High School. Initially involved in football, Bielenberg was subsequently invited to join the wrestling team during his freshman year. By the time he had completed high school, Bielenberg had won two state championships in freestyle wrestling, and one each in folkstyle wrestling and Greco-Roman wrestling.

Bielenberg enrolled at Oregon State University in 1974, recruited as a scholarship athlete by legendary wrestling coach and National Wrestling Hall of Fame Distinguished Member Dale Thomas.

Competing in the heavyweight division, Bielenberg won the national championship as a sophomore in 1975 after finishing fifth as a freshman to earn All-America honors. He was an All-American during his junior and senior years, when he finished third and second, respectively.

He remains second all-time in OSU history for wins with 165 and is the school's career leader in pins with 94. Bielenberg won 51 matches during his senior year, which is the second-highest win total for a season in school history. Having amassed an overall record at OSU of 164-15-1, Bielenberg was inducted into the OSU Athletics Hall of Fame in 1994 and was named to the Pac-12 All Century Team in 2016.

While still an OSU student, Bielenberg began to compete on an international basis, participating in the 1975 Junior World Championships. He was also an alternate on the 1976 Olympic team and wrestled in the 1978 World Championships, where he finished in a tie for third.