Plot hole: Immediately before the attack on Pony-That-Walks' village Capt. Brittles states that it's 12 minutes to midnight,and orders the attack. The attack is a surprise attack, yet all the warriors pile out of their tipi's fully clothed, painted and with their eagle feathers braided into their hair.

Audio problem: in the beginning of the movie there is a shot of the flag being raised over Fort Stark and the sound of a bugle is playing. The bugler is playing "Retreat" which is only played when the flag is coming down; he should be playing "Reveille".

Factual error: In the very beginning of the movie, the narrator says, "Pony Express riders know that one more such attack (referring to the Custer Massacre) would mean a hundred years before another wagon train crosses the prairie." Then they show a Pony Express rider supposedly carrying the news. But the Custer massacre happened in June of 1876, and the Pony Express went out of business in 1861.

Factual error: Near the end of the movie Capt. Brittles states that he's an officer of the U.S. Cavalry for four more hours, what he means is that his term expires at midnite that night , this would make the time 8:00 PM however when he makes this statement it is broad daylight.