George Sherman produced this film, and Michael Curtiz directed it. During much of the shooting, Curtiz was seriously ill: he died of cancer shortly after the film's release. On the days when Curtiz was too ill to work, John Wayne took over direction. When the film was completed, he told the studio that he did not want credit as co-director and insisted that Curtiz's name alone appear as director. Wayne performed the same function in 1971 on "Big Jake (1971)," which was directed by Sherman, who took ill during production. Wayne directed the film on the days when Sherman couldn't and again insisted that he not receive co-director credit.
Because of Lee Marvin's performance as Tully Crow, John Wayne recommended Marvin to John Ford as the eponymous villain of The Man Who Shot Liberty Valance (1962).
Paul Regret (Stuart Whitman) was the lead in the novel, and Capt. Jake Cutter (John Wayne) had to be amplified for the film version.
On the first day of filming, John Wayne reprimanded third assistant director Tom Mankiewicz for wearing a John F. Kennedy button. He told him, "I'd take that button off if I were you. We don't advertise socialists on my set." Wayne had campaigned for Richard Nixon in the 1960 U.S. Presidential election, and blamed Kennedy for losing the Bay of Pigs invasion.
Paul Wellman wrote the novel with Cary Grant in mind as Paul Regret. However, by the time the film was made, Grant was too old for the part, and would never have taken second billing to John Wayne.