 In stage productions, the horses are portrayed by human actors, often heavily built, athletic men wearing tribal-style masks.Lumet did not believe this could adequately be done in a film version, concluding a degree of realism was required, "because the reality he [Alan] was being watched in was going to create the dilemma within him".For horse-related stunts, the filmmakers consulted Yakima Canutt, who had previously worked on almost all of John Wayne's early western films.