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.
For Ann-Margret, 1972 was a difficult time in her life. Earlier in the year, she was seriously injured while performing onstage in her Lake Tahoe show, necessitating physical therapy. In addition, the extensive horseback riding required by the script meant that she had to overcome her fear of horses. Before shooting began, she took riding lessons from Chuck Hayward, a stuntman known for his horsemanship. Wayne also offered her moral support. She recalls: "Duke was still a strong, rugged, formidable man, larger-than-life and incredibly personal. He was a big teddy bear, and we got along famously. Duke gave me the confidence I lacked."