The Novel
Read it way back in '72 after seeing the film for the first (of about fifteen) times in the theater. The movie was great, and a pretty faithful adaptation, to be sure. Here are a few differences between the two:
In the book, Andersen and Nightlinger knew each other from other cattle drives. Nightlinger was Andersen's regular cook on drives, and had been for years.
Nightlinger was famous for his creative cursing. He called somebody a 'rancid old parallelogram' at one point.
None of the other boys liked Weedy because he was very religious.
Every single one of the boys, except Weedy, DID go visit the soiled doves' wagon. Cimarron, being the only one who wasn't a virgin, went first.
Before dragging the kid into the river, Long Hair burned the bottoms of his feet with a red-hot knife or poker.
Just before Wil Andersen died, he ordered the boys to take back the herd from the rustlers. I'm not sure, but I think Nightlinger objected, saying the boys shouldn't die over a bunch of cows.
I wish I could remember more because it really was a great book.