 While acting in "Harvey", he made his motion picture debut in 20th Century-Fox's Christmas classic "Miracle on 34th Street" (1947).Gist was also seen on Broadway in director Charles Laughton's "The Caine Mutiny Court Martial" (1954) with Henry Fonda and John Hodiak.While shooting "Operation Petticoat" (1959), Gist told director Blake Edwards that he was interested in directing.