Robert Mitchum visited his son Christopher Mitchum during filming. Director Howard Hawks asked the elder Mitchum to reprise his El Dorado (1966) role as a drunken sheriff, but Mitchum claimed he was now retired. John Wayne responded, "Mitch has been retiring ever since the first day I met him."
John Wayne was in poor health during filming, and frequently had great difficulty getting on and off of his horse. He was also still recovering from tearing a ligament in his shoulder while filming The Undefeated (1969).
John Wayne felt that Jack Elam had stolen several scenes from him in this movie, and therefore vetoed the casting of Elam as Grady in The Train Robbers (1973).
During a break in filming, John Wayne collected his Best Actor Oscar for True Grit (1969) from Barbra Streisand at The 42nd Annual Academy Awards (1970). When he returned, every member of the cast was wearing an eye patch, including his horse.