Corrected entry: Midway through the film we see a sign that states the distance to El Paso. The surrounding country is grasslands. There are no extensive grasslands anywhere close to El Paso.
Corrected entry: The postcard that Ennis initially receives from Jack is dated September 1967. Not only does the date stamp not show the day the card was mailed, just the year, but also there is no ZIP code on the address. The USPS began requiring ZIP codes on July 1, 1963, and this post card - mailed more than three years later - never would have been delivered without a ZIP code.
Correction: The US Postal Service created the zip code service back in 1963, but has NEVER required it to be used. You can mail a postcard even today and, without zip, it will get there if the rest of the address is genuine. It just might take a bit longer.
Corrected entry: The film's unexpected success at the box office has been attributed, at least in part, to the free publicity generated by the plethora of gay-cowboy jokes on late-night TV.
Correction: Too common and obvious to be trivia.
Corrected entry: In the opening scene of the film, set in 1963, several shots show a beat-up, rusty white pickup truck abandoned in a field. The truck is a 1963 Chevy, which would have been brand new at the time.
Correction: As you say, the movie is set in 1963 so the dilapidated 1963 truck may be improbable but not impossible and therefore, not a mistake.
Corrected entry: When Jack and Ennis reunite for the first time in four years, and they are kissing at the bottom of the stairwell, Ennis' shirt becomes unbuttoned and disheveled (several buttons are undone and his undershirt is visible). In the next shot it's completely buttoned and unwrinkled.
Correction: There was plenty of time between those two shots, and if I were Ennis, of course I would have straightened and buttoned my shirt again.
Corrected entry: Different postcards: The mountain on the picture postcard that Ennis initially receives from Jack is a different mountain that is pictured on the postcard in the final scene of the movie that Ennis has saved in his closet over the two shirts that he took away from Jack's parents' home.
Correction: The postcard in the closet is the one that Ennis bought at a local store. He looked at a rack of postcards and asked for a Brokeback Mountain postcard. The shopkeeper told him he will be getting forty of them coming in an order, to which Ennis replied, "I just need one".
Corrected entry: When Ennis goes up to Jack's boyhood bedroom you see the area at the top of the stairs is empty. But when Ennis is in the bedroom and looks out of the bedroom towards the stairs there are clothes hanging along that wall.
Correction: When Ennis glanced up and noticed the clothes hanging, they weren't on the landing area to the bedroom, they were in a small wardrobe - this would have been to the left of the door as he walked in but didn't notice it immediately as he had his back to it when approaching the desk.
Corrected entry: Where Jack and Ennis argue (in their last meeting) in Ennis' shots, it is a sunny day (you can even see shades in the ground), but in Jack's shots it is cloudy.
Correction: If you've ever lived on the Prairies or foothills, where the movie was filmed, you'd see that kind of thing often. It can be sunny to the west, and cloudy to the east, especially if there is a chinook wind pushing the clouds eastward. Happens regularly.
Corrected entry: Jack's daughter grew up in Riverton, Wyoming yet speaks with a Southern accent. While Jack is from the South, her mother isn't, and it's not very likely that she wold have picked up the accent growing up with only one Southern parent.
Correction: Not very likely doesn't mean impossible, so this can't really be considered a mistake.
Corrected entry: When Jack hits Ennis in the face on the mountain, Ennis wipes his nose on his left sleeve. When Ennis find the shirts in Jack's closet, the blood is on the right sleeve.
Correction: Ennis does, in fact, wipe his nose on his right sleeve, so there is no discontinuity.
Corrected entry: Despite the movie taking place over a 19 year span, the director (and make-up department) made no effort whatsoever to age the characters even a single day.
Correction: This is simply not true. there are subtle but realistic changes to the characters' appearances, appropriate for the time passage. For example, Jack grows facial hair and gains a bit of a belly; Ennis's face gets more worn-looking especially around the eyes; both men develop touches of gray in their hair; Lureen develops cigarette-stained teeth, worn eyes, and damaged hair from years of bleaching. The difference in one's appearance from 20-ish to 40-ish is noticable, but not extreme.
Corrected entry: Near the beginning of the film, a freight train passes by. It is without a caboose. Cabooses were removed from North American freight trains only in the 1990s.
Correction: I'm sure it's possible that at least once before 1990 a caboose was not put on a train, either intentionally or by accident.
Corrected entry: At the end of the movie, when Ennis enters his trailer, the door is hinged on the left, causing it to swing clockwise. When he later opens the door from the inside, the door is hinged on the opposite side, causing it to swing counter-clockwise.
Correction: This is because it is a different door. Fire regulations deem that all trailers/mobile homes must have two doors on the same side. The door that Ennis opens is the second door further down the trailer, where he's right next to the place he's hanged the two shirts and postcard.
Corrected entry: The Elks Lodge down the street from Ennis and Alma's apartment is numbered 129. Elks Lodge 129 is actually located in Washington Court House, Ohio. (01:00:20 - 01:13:30)
Correction: There are roughly 15 elks lodge's with the 129 address. And a total of 2100 Elk Lodges throughout the United States.
Corrected entry: Carhartt did not put their symbol on the outside of their clothing in the 1960's, 70's and 1980's, yet Ennis is wearing a Carhartt jacket with the symbol on the front.
Correction: According to Carhartt customer service, "the Carhartt originated in the 1960's and in some form or another, we have always displayed our logo, whether that was a cloth patch or on buttons such as on the bib overalls."
Corrected entry: In the last meeting between Ennis and Jack on Brokeback Mountain, Jack has had a moustache for several years. In one closeup shot of Jack's face, he is without a moustache, and then the next shot is of him having one.
Correction: In the last meeting, there is a scene that takes us back to the year when they fell for each other. They're standing next to a fire, Ennis puts his arm around Jack, and Jack caresses it with his face. That's when we see Jack without his mustache. After that brief moment, which was almost 20 years before, we see Jack with his mustache.
Correction: In the Chihuahua Desert, there are extensive grasslands; some of the most important in the United States.