According to Peter Bogdanovich in "Pieces of Time" Richard Widmark stated he had more fun on this film than any other. "I'm a little deaf in this ear . . . and [John Ford]'s a little deaf in the other, and [James Stewart's hard of hearing in both! . . . So all through the picture, all three of us were goin', 'What? What? What?'"
This was the last film in which James Stewart wore his familiar cowboy hat. Up to this point he had worn it in all his westerns since Winchester '73 (1950). This was Stewart's first film with John Ford and Ford didn't want him to wear it, as he thought it was the worst-looking cowboy hat he had ever seen. Ford quipped, "Great, now I have actors with hat approval." As Stewart said in the documentary, A Wonderful Life (1989), Ford relented but got back at Stewart in their next western, The Man Who Shot Liberty Valance (1962), when he didn't let Stewart wear a hat at all.
Richard Widmark was initially reluctant to make the film, since he felt he was 15 years too old for the young lieutenant he played.
The dialog in the scene where James Stewart and Richard Widmark sit by the river was largely improvised.