Riders of the Purple Sage is a Western novel by Zane Grey, first published by Harper & Brothers in 1912. Considered by many critics 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."
http://en.wikipedia.org/wiki/Riders_of_the_Purple_Sage
Pearl Zane Grey (1872 – 1939) was an American author best known for his popular adventure novels and stories that were a basis for the Western genre in literature and the arts. He was a major force in shaping the myths of the Old West; his books and stories were adapted into other media, such as film and TV productions. He was the author of more than 90 books, some published posthumously and/or based on serials originally published in magazines.
http://en.wikipedia.org/wiki/Zane_Grey
