Zane Grey 
From Missouri and Riders of the Purple Sage 

From Missouri — The story of a young school teacher who comes out West from Missouri, because of a series of letters from a Mr. Owen, who says there is a job there for her. The Riders of the Purple Sage — Riders of the Purple Sage is a Western novel by Zane Grey, first published by Harper & Brothers in 1912. Considered by scholars to have played a significant role in shaping the formula of the popular Western genre, the novel has been called "the most popular western novel of all time." (Goodreads)