What a great idea for a story! Setting it in the 20th century and having the protagonist be a western history writer was a great idea.
Sadly, it didn’t live up to its promise. The action becomes ridiculously repetitive and the bad guys remarkably incompetent.
As with so many L’Amour novels the hero HAS to climb a cliff, have a gunfight and a fistfight, and get the girl in the end. And her ranch is saved.
Rewritten, it’d make an interesting film.