Continuity: There is no way the cow (a Hereford I think) could have given birth to that calf (a Jersey or something like that). [The mom is a mixed-breed BEEF cow, the calf a purebred Jersey DAIRY calf. An amazing feat of animal husbandry.]
Great sites
Mistakes
During the scene where Cookie is drunk and takes off in the covered wagon, if you look under Cookie's seat you can see a person in a dark shirt inside the wagon. It can't be one of the movie characters because when he heads towards the cliff, he's the only one who jumps out of the wagon and in the next scene only the horses are buried. See more...
City Slickers (1991)
starring Billy Crystal, Bruno Kirby, Daniel Stern, David Paymer, Jack Palance (add more)
City Slickers mistakes
Continuity: During the scene where Billy Crystal and Jack Palance are riding and talking about the "one thing", notice that Jack Palance's cigarette has a huge ash, then has just been lit, then has a huge ash again.
Continuity: When Mitch shows Ed and Phil the coffee grinder, Ed has a smear of shaving cream on one side of his face. When Ed jumps on his horse during the cattle stampede and says 'I'm gonna die, I'm gonna die.' there is shaving cream on both sides of his face.