The shooting gallery at the fair has only 10 targets (2 rows of five), but Anna shoots 12 for a perfect score. When she shoots, short cuts to the gallery show 10 targets, but 12 shots are heard and Anna wins the prize for perfect score.
When Albert is learning how to shoot, he cocks the hammer twice before starting to shoot. After the missed shots, Anna reloads the gun, then drops two bullets. When the angle changes, she drops 6 more.
Anna knocks out Clinch and then rides off to Albert's house with Plugger by her side. However when she gets to Albert's house, Plugger isn't there. He's also missing when she runs to Edward and Ruth's place to hide from Clnich. He reappears during the final gunfight between Albert and Clinch.
After escaping from Clinch, Anna runs to Albert's home to warn him about Clinch looking for him. She gets to Albert's house on a horse. After Albert dismisses her and tells her to leave out by the ridge, she doesn't leave with her horse.
When Clinch and his gang are chasing Albert on horseback -some shots show Clinch with 4 gang members while others show Clinch with 5 gang members.
In 1882, outdoor photography did not require the use of flash powder, the sun would provide enough light. In average daylight, someone posing for a photo would need to stay still for 5-8 seconds, not 30 seconds.
When Albert and Charlie are standing in the street for a gunfight several feet apart, based on their heights, their shadows are not close enough to depict the obscene act depicted. One person would have to be very short for the body parts to line up as shown.
A photo at the beginning shows a woman who is supposed to be Miss America 1880. Miss America started in 1921.
After the photo shoot disaster at the Fair, two cowpokes shoot the unfortunates with Winchester model 94 lever action rifles first manufactured in 1894.
As Albert flees Clinch from his family's farm, the tall objects in the distance are rock formations, not city skyscrapers.
When Anna comes to the party in a big dress she reveals is a large metal frame underneath to keep the shape. Soon after, when she drinks with Foy, she sits down with no trouble, and the frame has disappeared.
When Albert is learning to shoot, he misses the target several times, but no bullets hit the ground anywhere.
When Anna approaches Clint's unconscious body to plant the daisy in his crack, Clint visibly clenches for a second just before she inserts the flower.
Living in 1882 in the American West, Anna has shaved armpits.
Albert calls marijuana "pot". The nickname "pot" comes from the Spanish word "potiguaya", which means "marijuana leaves". It's a contraction of "potación de guaya", an alcoholic drink made of marijuana leaves soaked in brandy or wine. The name became popular in the United States in the late 1930s and early 1940s.
Electric welds apparent on photographer's flash pan and on windmill vanes. Electric arc welding had been invented by the early 1880s, but it wasn't common until well into the 20th century.
One of the film's pistols is a Webley MKIV, first manufactured in 1915.
Albert escapes on a train pulled by a Denver & Rio Grande Western K-27-class steam locomotive, first built in 1903.
The movie takes place in 1882. The characters meet and take drugs with Apache Chief Cochise, who died in 1874.
The opening credits set the movie in Arizona. Several scenes show Monument Valley, which is in Utah.
When Albert escapes on the train, you can see a modern city on the horizon.
Back to the Future III takes place in a town named Hill Valley California; while the town in this film is called Old Stump and is supposedly in Arizona.
"Rough men" might have worn hats indoors, but dandies like Foy would observe the Victorian social norm and remove their hats indoors.
When Foy challenges Albert at the shooting gallery, he proposes to make it a nickel a target. Albert answers it's too much for him, and brings it down to a penny. After mocking him, Foy refuses to comply, by saying "No, no. A penny it is", so actually agreeing to Albert's proposal.