John Wayne fractured two ribs shortly before shooting began, causing such pain that he had difficulty sleeping at night. As a result, the action scenes had to be scaled down to accommodate his condition, but the tough-minded actor refused to delay the shoot, displaying the same determination and sense of personal integrity which distinguished his on-screen persona.
Director Burt Kennedy wanted to cast Jack Elam as Grady. However John Wayne would not allow this, because he felt Elam had stolen too many scenes from him in "Rio Lobo (1970)."
The town in the film was constructed at a cost of $100,000.
Michele Carey who had co-starred with John Wayne in "El Dorado (1966)" was his first choice for the female lead in both "True Grit (1969)" and this film, but both times her schedule did not allow her to commit to the filming of either.
Rod Taylor finally got to work with John Wayne after being considered for "Rio Bravo (1959)," walking out on "Circus World (1964)," and being passed over for "The War Wagon (1967)." In later years Taylor would claim to have been good friends with Wayne, although others who knew the older actor have doubted this.