To the Last Man: A Story of the Pleasant Valley War is a western novel written by Zane Grey. The story follows an ancient feud between two frontier families that is inflamed when one of the families takes up cattle rustling.
http://en.wikipedia.org/wiki/To_the_Last_Man_(Zane_Grey_novel)
A movie based on the novel was made in 1933.
http://en.wikipedia.org/wiki/To_the_Last_Man_(1933_film)
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