Goofs

When Mortimer unrolls the wanted poster before sliding under the door, the poster has a curled-up appearance. Once it's under the door inside the wanted man's room, it is completely flat.

After Monco's cigar is shot to a very short length by one of Indio's gang, subsequent shots have it both longer and then shorter again.

When Monco and Mortimer are loading their guns, getting ready for the final showdown, they have a few bruises on their faces from their beating. Once the shootout begins, they no longer have any bruises.

When Monco enters the saloon at White Rocks, his hat and poncho are dripping wet. In the next shot, they are totally dry.

During the poker game between Monco and Cavanaugh, in some shots there are just two poker hands on the table, and in other shots there are four.

When Monco's hat is shot off his head and down the street by Mortimer, ricochet sounds are heard; this would happen only if bullets hit solid objects like metal. (This distorts the bullet and causes it to to bounce off and tumble, which causes the characteristic whine.) In fact, most shots are accompanied by the sound of ricochets.

When Manco rejoins Indio's gang breaking into the stolen safe, the valley they are in has numerous date palms. Although some date palms were imported to California and Arizona, there weren't any in New Mexico, and none were in use until the 1900s.

Col. Mortimer (Lee Van Cleef) is browsing a newspaper (El Paso Tribune) with the publication date of Monday June 15 1872. The actual day of June 15 1872 was Saturday, not Monday.

In both dream scenes, Mortimer's brother-in-law was shot three times at close range. There are no bullet holes front and back or in the wall behind him.

When Mortimer comes into the saloon looking for Guy Callaway, the piano player is performing in the Stride style, which wasn't invented until the 1920s.

When Mortimer is browsing in the local newspaper all pages are identical.

He was browsing in the tear sheets of the newspaper's morgue where they keep back issues. They were bound in hardcovers. There was more than one copy of each.

The young man whom Indio kills in the flashbacks is shot three times, yet there is no evidence of bullet holes or blood. However, this is because it is Indio's memory and not an actual shooting.

Face on wanted poster of Indio is a high-contrast reproduction of a modern style photo.

Indio's high-contrast repro is obviously a continuation of the previous shot of his insanity face. This is Artistic License.

Indio's image on his wanted poster looks exactly like him, but the face on the wanted poster of Guy Callaway, Mortimer's first target - looks nothing like him.

It was never explicitly stated in the movie that the man shot by Mortimer was actually Calloway, not even when the bounty was paid, and he clearly did not look like Calloway.

Monco advises Indio not to ride north along the "Rio Bravo" but to ride south. The Rio Bravo (otherwise known as the Rio Grande) does not run to the north from El Paso but adjoins the city to the south. If they ride south to Mexico, they would have to cross the Rio Grande.

The Rio Grande certainly does go north, all the way from its headwaters in south-central Colorado.

While breaking Indio out of jail, one of the bandits shoots a prison guard, who reacts to the bullet before he is shot.

During the "Hat Duel", both Monco and Mortimer shoot each other's hat numerous times. However, when they are talking in Mortimer's hotel room afterwards, their hats are sitting on a table, and only one bullet hole is visible in each.

After Monco rides into Agua Caliente, he shoots some apples off a tree for a little boy. This cements Indio's suspicion that he's not ruthless enough for a bandito, so he must be a bounty killer.

When Manco and Mortimer exchange dialogue at the end of the film about the reward money and possibly having a partnership, over Manco's right shoulder, a woman and a child are visible walking around in modern clothes.

As Monco is riding away from the sheriff's office, just after the 18 minute mark, the house to his left shows a view through a side window to daylight, revealing that the building has no roof and is just a set.

The car seen driving down the dirt road is visible during the conversation from the passenger on the train. This occurs before Mortimer lowers the Bible, when the traveling salesman says the train does not stop in Tucumcari. The car is seen in the distance, moving from lower right to upper left and driving at high speed.

In the hilarious scene where Monco and Mortimer shoot each other's hats, the lights of an airplane can be seen flying over Monco's head in one quick shot.

Tucumcari wasn't founded until 1901.

Mortimer smokes a meerschaum pipe throughout the movie, which is historically accurate; however, the pipe stem is obviously Lucite, a plastic first marketed in 1933. An 1860s pipe stem would be carved of amber, ivory, antler, or bone.

When searching old newspapers to determine who is competing with him in El Paso, Colonel Mortimer discovers a front page of the El Paso Tribune from June 15, 1872 with a story about Monco that includes a photograph. The first photograph printed in a newspaper would not occur until March, 1880. In addition, the headline above the photo is of a modern brush-style linotype font.

As Indio tells the story of the safe to his men, a crew member wearing a light blue shirt entering the left side of the frame can be seen in the background in one of the closeup shots of Nino.

When Monco rolls Groggy over with his boot after killing him, the fake blood capsule that Luigi Pistilli used for his death scene can be seen. Clint Eastwood steps on it with his boot to hide it.

An unrelated map of Uruguay is seen hanging on the wall in Tucumcari's Sheriff's Office around the 12:00 minute mark. Uruguay has nothing to do with the film and lies thousands of miles away from Tucumcari.

There are no cacti visible. Cacti are found only in North and South America, making it obvious that this was filmed in the Old World; in this case, Spain.

The bank of El Paso is built with concrete instead of wood, with a safe that's disguised as a drinks cabinet, and a guard inside and some guards outside when it closes. So it makes no sense that with all that careful planning, that not one person wouldn't have the intelligence to realise that in order to make it even more secure, they should have all four guards outside it walking in different directions and cross each other during patrol instead of walking around it together in the same direction.

The lawmen in the town of El Paso clearly aren't cowards. This is evident when they all rush off to the town of Santa Cruz where they believe El Indio is. And they are in charge of a town where protecting the bank is obviously of vital importance. Yet when Manco and Mortimer are in the street, shooting at each other's hats, no one in authority is anywhere to be seen.

There is no way the baby shown is 18 months old, perhaps a year old at most.