Anachronisms: The film is set in 1865 yet several Colt Model 1873 Single-Action Army Revolvers are seen which were not available until later.
Anachronisms: When they are driving the cattle and go to the aid of the wagon train, a communications mast can be seen on the hill in the background of one shot of the five horsemen. The next shot is a closer view of one rider and the mast can be seen even more clearly.
Factual errors: The film gives 14 August 1865 as the completion of the first cattle drive on the Chisholm Trail. However, the first cattle drive on the Chisholm Trail started and finished in 1867, two years later.
Crew or equipment visible: An equipment shadow tracks across the wagon as the camera pans from Groot to Dunson during their first night on guard at Red River.
Continuity: During the cattle stampede, Dunson, Matt and the other cowboys saddle up and try to turn the herd. Process shots of each cowboys are inserted in the scene. Every cowboy is riding the same dummy horse and saddle with a very large Mexican saddlehorn.
Continuity: Inside the tent, during Tom and Tess's conversation, the lamp hanging between them changes positions and disappears between shots.
Continuity: Near the end of the film, when Tom walks toward Matt, his shadow changes repeatedly from one shot to another.
Continuity: When Dunson is standing next to his horse after Mathew Garth takes the herd from him, he clearly has a belt full of cartridges, but later on Mathew confirms to Groot that he took all of Dunson's cartridges.
Revealing mistakes: Matthew Garth seems to beat Thomas Dunson to the draw in a mock contest orchestrated by Dunston and Groot Nadine. However the gun is already in Garth's right hand in order to fool the audience, as evidenced by the his empty holster as he walks away.
Continuity: Near the end of the movie, John Wayne is shot. After a fight with Montgomery Clift, Wayne is miraculously well again.
Continuity: As the men and the herd approach the railroad, the clouds change from scattered to clear, to overcast as they approach the town of Abilene.