Horse trainers Glenn Randall and his sons J.R. and Corky Randall began their international search for a black Arabian to play The Black in the upcoming film. They found Cass Ole at his ranch in San Antonio, and his temperament and appearance suited him for the role. His owners stipulated that he was not to be used in the running or swimming scenes, so three other horses were obtained for use in those shots, as well as for stunts. Cass Ole and his fellow horse actors trained at a California ranch for several weeks before filming began. He had sessions with the young actor in the lead role, Kelly Reno, so the two could become familiar and get used to working with one another.