Do You Know the Most Famous Book Set in Montana?

I'm very surprised they chose this one out of all of them.

Business Insider did a list of the most famous books set in each state and they believe A River Runs Through It is the most famous one set in Montana. Which is very surprising to me due to the fact there are many great books/stories where Montana is the setting and they chose A River Runs Through It.

I have no problem with that book by the way. It's a fantastic read, and I enjoy it thoroughly, but the problem is there are a few that could easily be just as famous.

Did you know that The Horse Whisperer was set in Montana? Or Montana Sky by Nora Roberts (this lady has so many books it's insane)? Another one that I know very well but technically it's a novella (short story) is Legends of the Fall.

I think any of these books could be the most famous set in Montana, but A River Runs Through It is probably the most well known/most sold book out there today.

Did I miss any other books that were huge that were set in Montana? Let me know.