B. M. Bower 
Phantom Herd [EPUB ebook] 

Luck Lindsay is a movie creator and director, specializing in "Westerns". This is in olden times when movies were silent. But, he got sick of the formulaic shoot-em-up movies that Hollywood was turning out and wanted to produce something that represented the "real" west of olden times, i.e. real cowboys chasing real cows in difficult situations, but still succeeding. Luck meets an old timer at a train station and is directed to a slice of Montana where he finds some "real" cowboys. (Goodreads)