In one of many 'show the majestic view as they ride' scenes, you can see the cooling tower of a nuclear reactor. [This film was filmed entirely in South Dakota. There are no nuclear reactors in South Dakota.]

When the Sioux are surrounding the Last Pawnee in the creek, they are in a circle around him and all fire their rifles at the same time. In this situation a few Sioux would have been shot. [Not necessarily. Most of the Sioux are sitting atop horses and aiming DOWN at the Pawnee warrior.]

Why does Stands With a Fist have shoulder-length, layered hair and bangs? Wouldn't her hair be all long and natural, like every other woman in the tribe? [It's a Native American custom for someone in mourning to cut his/her hair. Stands With a Fist has recently lost her husband as the movie opens.]

During the buffalo hunt, Dunbar shoots his rifle several times without ever reloading it. When he shoots at the buffalo charging at Smiles A Lot, Dunbar has to cock his rifle between each shot, yet can fire two shots at the downed buffalo without cocking the rifle between shots. [You dont see Dunbar reloading his rifle when he shoots at the pack, because the indians are filmed between them shots. And in my dvd- version of this movie Dunbar does cock his rifle in between when he takes the two shots at the downed buffalo.]

In the winter scene you can clearly see that the people have no visible breath, despite there being snow all around. [I live in New Hampshire, and it must be quite cold, around 20 degrees to cause breath to fog instantly. Also, who's not to say that the temperature is above freezing? There are simply too many "ifs" in the situation.]

A skittish wolf like Two Socks would never position himself so close to an Indian scouting party, as is revealed after he is shot by the soldiers. [I think the point is that his bond with Dunbar is stronger than his natural fear. Not only is he in close proximity to the U.S. soldiers, but even after they shoot at him multiple times he stays where he is, rather than run away. This has to be more frightening than being near a very quiet group of Indians.]

Dunbar washes his face and forehead, (we assume to remove the blood from what appeared to be quit a nasty injury), after being knocked out on the door frame yet, there is no sign of cuts, scrapes or bruising on his forehead. [If you look closely as Dunbar is sponging his forehead with his washcloth, you can see a horizontal "cut" and "bruising" at the top of his forehead.]

Kevin Costner would not have that many Henry Repeating Rifles in 1865 because a) only a few thousand were supplied to the whole U.S. Army until around 1866 and each rifle cost about $42.00, which was half of a year's salary back then and the bullets for it were about $10.00 per 1,000. b) The rifles used were the "King's Patent Henry Rifle" which wasn't out until 1866. The original Henry had a loading tube under the barrel, not one on the side of the breech.  Even if this movie was supposedly in 1866, they still would have not been using those repeating rifles due to lack of supply. c) The ammo used were the larger, more modern rounds. [The extra rifles that Dunbar has are standard issue US Cavalry rifles. Dunbar owns the only repeating rifle used in the film.]

When Dances with Wolves walks romantically hand in hand with Stands-with-Fist, cottonwood trees are bearing cotton, though the bare limbs clearly show it was shot in autumn. Cottonwood trees pollenate (like every other plant) in spring. [In fact, as per written in the script by Michael Blake, those are cattails - not cottonwood - which do 'fluff' in the fall, leaving bare limbs that may be mistaken for cottonwood.]

Shortly after Kevin Costner arrives at his deserted post and decides he is tired of waiting for the Indians to come to him, he decides to "ride out and meet them". There is a scene where he is dressing in his uniform to prepare for this visit, where at one point he fastens a roughly 6-inch long (presumably) brass "cover" over the buttons on the front of his uniform. He then uses a rag to shine between the buttons for a moment. This "cover" has disappeared in the next shot when we see Costner fully dressed and walking towards his horse. [I believe this is actually a plate used to protect the uniform as he shines up the buttons, to be slipped off when the buffing is complete.]

At the beginning of the movie Lt. Dunbar is waiting to have his foot amputated, but later on in the movie when he's taking a bath in the river, both his legs are fine and there are no injuries. [Dunbar has both feet because the General distinctly ordered his men to "bring up my ambulance and bring my surgeon with it" and told Dunbar to "rest easy, son, you'll keep your foot. As God is my judge you'll keep it."]

At the end of the movie, just before Dunbar arrives at the winter camp in the mountains, after being rescued by Wind in his Hair and his men, an old Indian man looks up and see them coming down the mountain. The old man is wearing thermal underwear under his leather tunic. [Apparently around in those times]