Riders of the Purple Sage(1918)

Lassiter quits the Texas Rangers and spends his life in pursuit of a group of Mormons who kidnapped his married sister. In a town on the Utah border, he meets the Withersteens and falls in love with their daughter, Jane. He also befriends Venters, and helps him track down some bandits who have been rustling the Withersteens' cattle.