Overhead electrical power lines are visible during the buffalo hunt.
The banner flying over Fort Sedgwick is the fifty‑star flag, rather than the flag that would have flown during the Civil War.
In the film's final scenes, United States military personnel discover a camp that has just been vacated. Many of the soldiers are shown wearing overcoats with rank stripes and yellow lining. The action is set during the American Civil War (1861–1865), yet overcoats with coloured lining and rank stripes were not introduced until 1883.
The dove in the old fort is a Eurasian collared dove, a species that had not yet been recorded in North America at that time.
In 1863 General Tide is depicted wearing three stars, the insignia of a lieutenant-general. There were no lieutenant-generals in the United States Army at that time.
At the time in which this film is set (the US Civil War, 12 April 1861–9 May 1865) the site was not called Fort Sedgwick; it was known as "the Post at Julesburg Station". The post was not renamed Fort Sedgwick until 27 September 1865, several months after the war had ended, in honour of the late Major-General John Sedgwick.
As Dunbar pulls a dead deer from the pond at Fort Sedgwick, tyre tracks can be seen on the hillside in the background.
The apple lying beside Dunbar on the battlefield, following his return from the operation, belonged to a variety that had not yet been developed at that time.
A round tin kerosene can, shown in close-up for a few seconds while Dunbar prepares to set fire to rubbish left at the abandoned outpost, is clearly marked 'NPRY' for the Northern Pacific Railway — which did not lay its first track until roughly five years after Dunbar is meant to have arrived at the post (and that track was in a different state).
By the fireside, an elder is discernible with a modern-day collar tucked beneath his costume.
During the Pawnee raid on the Sioux camp, one Pawnee is seen wearing a Pattern 1883 cavalry greatcoat, notable for the cape's yellow lining. Greatcoats from the 1860s did not have a yellow lining.
Upon Dunbar's arrival at the settlement, workers are sawing rough planks from logs at a makeshift sawmill. No nearby woodland is visible, nor is there any apparent means of transporting such large timbers from a distant location.
Towards the end, when the winter camp is first shown, an elder tends a campfire; as he looks up the collar of his costume parts, revealing a long waffle-weave undershirt beneath.
During the buffalo-hunt sequence, one can notice fence posts streaking past.
In the sequences set at Fort Hays, the windmill that appears in several shots is anachronistically modern. The film is set in 1863; the windmill shown is a steel, self-lubricating design, a type that was not developed until after 1900.
Fort Hays (misspelt as "Fort Hayes") appears in the film. The film opens in 1863, but Fort Hays was not established until two years afterwards and did not receive its present name until the following year.
The film depicts European-American settlers hunting bison solely for their hides. That was not the reality in 1865; hunting for hides did not begin until 1871, and even then settlers still hunted bison for their meat as well.
Mary McDonnell's hairstyle was a contemporary 1980s look that would have required professional salon techniques — a hairdryer, the use of a hair iron, meticulous cutting and styling products. She stood apart from the Sioux women of the tribe, who all wore their hair in braids, as was customary.
The muskets issued during that period were rifled rather than the less accurate smoothbore arms of earlier decades. Even so, smoothbore muskets would have been capable of reasonable accuracy at those distances.
The song Kevin Costner sings while washing his clothes and taking a swim in the pond is "Soldier, Soldier, Won't You Marry Me?", which was first written in 1903.
Timmons and the others are shown wearing trousers with belt loops. Belt loops did not appear until 1922.
Lieut. Dunbar rides an entirely black 1872 McClellan saddle, whilst the standard-issue saddle at the time was the 1859 model, with a rawhide-covered tree and black rigging. One of the two saddles Costner used in filming was sold by Bonham's auction house in 2013.











