Zane Grey 
Riders of the Purple Sage [EPUB ebook] 

The canyons and sage plains of Utah have a dangerous beauty. Skilled riders must go out every day and night to protect the herds and the homesteads from cattle rustlers. Stories of a masked man and a lone gunman looking for vengeance have spread across Utah. There has long been a feud between Gentiles and Mormons. A feud that Jane Withersteen, daughter of the man who founded the Mormon settlement of Cottonwood, chooses to ignore. When Mormon Elder Tull discovers that the woman he means to make one of his wives has offered hospitality to an outsider he vows vengeance but he underestimates her courage and the determination of the riders of the plains.