Continuity mistake: When Kevin Costner gets hit on the head by the top frame of the door, he is knocked out unconscious. Yet, when he gets back up after regaining consciousness, the blood from is head had been running down his nose. Don't you think that as he was lying down in a horizontal position, the blood would run down over the eyes towards the ears?
Continuity mistake: The piece of meat that Dunbar offers the wolf changes shape and size dramatically throughout that scene.
Continuity mistake: When the Sioux men come to steal Dunbar's horse, Dunbar jumps into waist-deep water as he runs toward the corral. As soon as he climbs the river bank, his pants are dry.
Continuity mistake: When Cisco comes to Dunbar on the morning after the hunt, Cisco's "US" brand is missing.
Continuity mistake: Dunbar's jacket has yellow officer tabs on the sholder for Cavalry, but after he gave it to Wind in His Hair, the officer tabs are now blue for Infantry.
Continuity mistake: At the close of the buffalo hunt, Wind in his Hair cuts out the liver of the buffalo, holding it in two hands. He stands to take a bite out of it and it's already about half its previous size. When he hands it to John Dunbar, it shrinks dramatically in size again, and is a different colour and shape.
Continuity mistake: After Dunbar and Timmons have arrived at Fort Sedgewick and they realize everyone is gone, after Dunbar says "Not at the moment, we don't know what happened," the shots of Timmons alternate from having no egg on his face to having a lot egg on his face, especially on the tip of his nose. (00:25:30)
Continuity mistake: When Dunbar 1st finds a bloodied Stands with a Fist mourning on the prairie she has long hair extensions. When he carries her back to the tribe her hair is shoulder length.
Continuity mistake: The Civil War battle scene has trees already turning fall colors, and the cornfield is already showing frost damage with dying top leaves. The likely timing for scenery such as this would be about mid to late September. There wouldn't be enough time for Dunbar's leg to heal, then travel 1000 miles west, then establish rapport with the Sioux, then go on a buffalo hunt, then move to winter quarters before snow flies.