I nominate
Riders of the Purple Sage by
Zane Grey.
This is another book I have been meaning to read for years.
Here are two quotes from Amazon's webpage: "''Zane Grey epitomized the mythical West that should have been. . . The standout among them is Riders of the Purple Sage.'' --True West Magazine..."RIDERS OF THE PURPLE SAGE has played a significant role in shaping the formula of the popular Western genre. It remains a highly popular story in the cowboy genre to this day."
I have found two MR links:
https://www.mobileread.com/forums/sho...ight=Zane+Grey
https://www.mobileread.com/forums/sho...ight=Zane+Grey