Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This was Sam Peckinpah's first Western feature so it's pretty tame compared to his later films, but still controversial enough that he struggled to get it made.
Dragging a coffin across the desert (5 years before Django did it) Yellowleg, an ex Union Army Colonel, and Kit, a red-headed dance hall girl, stop to rest at some adobe ruins. The horse is hungry so Yellowleg kicks a pile of straw towards it, not knowing that he's also kicking a Western Diamond-backed Rattlesnake that's inside the straw. The horse panics and breaks its leg. Yellowlegs shoots the snake with his rifle then he shoots the horse in a Western Cliche two-fer. Surprisingly, for a movie, it was a perfectly believable accident. Even though the snake didn't try to attack anybody, it just tried to get away, it's understandable that it scared the horse.