Factual error: Towards the end when the cavalry uncovers the American flag, it has 50 stars.
Continuity mistake: When Rick Nelson tells Angie Dickinson to throw the plant pot through the window to distract the gunmen who threaten John Wayne he seems to have had a hair cut between scenes as his sideburns are halved by the time he reaches the street and grow again later.
Visible crew/equipment: Michael Pate is walking down the street in this western and as he passes a shop window you can see all the camera crew, the director, the arc lights etc.
Continuity mistake: When Bugs and Sam start their duel, you can see there is a glass at the end of bar counter. But when Bugs goes to the end of the bar, the glass has disappeared.
Continuity mistake: When Ben reiterates "We're going to Dry Fork", Randolph Scott's hands are joined on the reins. Shot from behind, you can see by the arm position that they are apart. (00:20:45)