Olsen, who was diagnosed with mesothelioma last year and had been undergoing chemotherapy, died Wednesday night, Utah State assistant athletic media relations director Zach Fisher said.

The burley giant from northern Utah joined Deacon Jones, Lamar Lundy and Rosey Grier on the Rams’ storied “Fearsome Foursome” defensive line known for either stopping or knocking backward whatever offenses it faced. The Rams set an NFL record for the fewest yards allowed during a 14-game season in 1968.

Olsen was rookie of the year for the Rams in 1962 and is still the Rams’ all-time leader in career tackles with 915. He was named to 14 consecutive Pro Bowls, a string that started his rookie year, and was voted to the Pro Football Hall of Fame in 1982.

Olsen was also an established television actor with a role on “Little House on the Prairie,” then starring in his own series, “Father Murphy,” from 1981 to 1983 and the short-lived “Aaron’s Way” in 1988.

Olsen was a consensus All-American at Utah State and won the 1961 Outland Trophy as the nation’s best interior lineman. The Rams drafted Olsen third overall in 1962 and he spent the next 15 years with the team before retiring in 1976.