Goofs

At the very end of the movie when Art and Gil get on their horses, you can see that Art steps up on something with his right foot, before he puts his other foot into the stirrup. In the next shot there is nothing for him to have stepped on.

During opening sequences when Fonda is at the bar, the whiskey he is drinking changes from clear to dark.

Gil Carter (Fonda) pulls his gun out twice when the mob first arrives at the Ox-Bow.

When the posse arrives at the Ox-Bow, after splitting into the three groups, Gil Carter (Fonda) pulls out his revolver and cocks it, then looks over at Gerald Tetley. Just a few seconds later, as Carter's group moves in, Carter again draws his revolver and cocks it.

When Juan Martínez (Anthony Quinn) is caught by the posse, he is told to raise his hands and he does so. In the next shot, however, his hands are on his knees again.

Just before the end, when one of the characters commits suicide, locked in his office, after the shot is heard, the door opens by itself.

Though the Mexican (Anthony Quinn) uses incorrect Spanish in responding "No sabe," his demeanor and his boast that he speaks 10 languages suggest he does this deliberately to show derision toward the posse.

Juan Martinez throws a knife that lands right next to Farnley's foot. If you look closely you can see a thin wire attached to the end of the knife, indicating that first the scene was filmed with the knife being jerked backwards by the wire, then the film was played in reverse, to give the desired illusion of the knife landing at Farnley's feet.

When the two cowboys ride out of town at the end (the same scene as at the beginning when they arrive), you see two huge trees in the back that have grown within a day.

Despite being of Mexican descent, Juan Martínez (Anthony Quinn) repetitively replies "No sabe" to questions. The correct conjugation of "I don't know" in Spanish is "No sé."