Born Robert Bradbury, he began appearing (at age 14) in semi-documentary nature shorts directed by his father, prolific silent director Robert North Bradbury; he later appeared in juvenile parts in some Westerns his father directed. In 1927 he began starring in cowboy films, maintaining his career in screen Westerns through the early '40s; he was one of the "Three Mesquiteers" in the series of that name. He also played straight dramatic roles, including the part of Curly in Of Mice and Men (1940). After the mid '40s he played character roles, appearing in films every few years until the early '70s. He was a regular on the '60s TV sitcom "F Troop."