'Don't believe love will find a way. I know all the ways.'
If I told you Jack Lemmon was in a Western as a hotel clerk who takes part in a cattle drive, you'd expect it to be a comedy, but that's not Cowboy. Oh, the scales fall from his eyes as to the reality of life on the range, but it isn't done in a way where he makes lots of hilarious mistakes. Glenn Ford probably would have killed him if he had.
Harris (Lemmon) loans Reese (Ford) some money for a poker game at the hotel. That's how Reese sees it, anyway, because he was drunk. Harris believes he's bought into Reese's operation, and now they're partners. Harris gradually learns how ugly the trail can be, and his idealism doesn't make many friends. Life is cheap, camaraderie among trail hands is a pipe dream, the cattle are all that matters. But he never takes Reese's repeated offers to take back his money and leave.
And gradually he learns the lessons, which makes him a mirror for Reese. Reese doesn't like what he sees looking back at him, leaving him to try and fix the damage, if he can.
There are moments in the film where you could see the potential for humor, but the movie avoids that. Probably the point. The audience thinks that with Lemmon it'll be funny, Harris thought this would be like his boyhood dreams, but it isn't on either count. The tomfoolery around the campfire gets a man killed. When one of the cowboys is about to get jumped in Mexico for flirting with the ladies, none of the other cowhands are much interested in saving his neck.
The movie did that a lot, subvert my expectations. At the start of the film, Harris is quite taken with a young Mexican woman staying at the hotel with her family. Her father's having none of it, and that line at the top was his. As it turns out he's one of Reese's cattle suppliers, I figured Harris joined on as a chance to see her again, no longer as a lowly clerk, but as a businessman. He does see her again, but she's married now, and Catholic, so I'm guessing divorce is out of the question. His attempt to do something brave to impress her is preempted by Reese, and there isn't that moment I expected where Harris does something that so impresses her father that he changes his mind. Doesn't happen. Harris and Maria have a final goodbye, but that's it. Harris never had a chance, whether she'd been married or not. Class issue, I suppose.
It's not a relentlessly depressing movie, I should make that clear. It ends on a high enough note. It just isn't the laughfest one might expect.