He died in a Californian hospital following a brief illness.
Following bit parts in movies, he moved to TV in the 1950s, starring in series such as Tales of Wells Fargo (1957-62), Iron Horse (1966) and Death Valley Days (1968-70).
In the 1980s he landed roles in Dallas and Dynasty plus guest roles in The Love Boat, Murder She Wrote and Fantasy Island.
His final role was Zeke in Harts of the West in 1993 before retiring from acting.
Robertson’s niece, Nancy Robertson, said, “I remember him as a larger-than-life fellow,” she said. “When he was in town it was always very exciting. It always meant something magical was going to happen,” such as another actor or performing artist accompanying him on his visits.”
Source: Washington Post