A. B. Guthrie Jr.

(Wikipedia) Alfred Bertram Guthrie Jr. (January 13, 1901 – April 26, 1991) was an American novelist, screenwriter, historian, and literary historian who won the Pulitzer Prize for fiction in 1950 for his novel The Way West.
... His novels include Murders at Moon Dance, which was published during 1943. The Big Sky appeared during 1947, with a young person's edition during 1950. The Way West, a novel about the journey of American expansion in the old west, was first published during 1949.
Guthrie continued to write predominantly western subjects, including the Academy Award-nominated script for the movie Shane during 1953 and the novel These Thousand Hills during 1956. During 1960, he published his first collection of short stories, The Big It and Other Stories. Fair Land, Fair Land, the third novel in the chronology begun with The Big Sky, was published in 1982. Continued