This collection consists of papers relating to the Barthelmess family of Miles City. There are two subgroups: one for Casey Barthelmess, Sr.; one for Christian Barthelmess. The Casey Barthelmess, Sr., subgroup consists of Barthelmess family Biographical Materials (1854-1995), Incoming Correspondence (1931-1988), Outgoing Correspondence (1926), Writings (1961, undated), Miscellany (1904, 1919, 1926), and Clippings (1935, 1948, 1968). The Biographical Materials include a family tree, photocopies of marriage records for Christian, Casey E., and Catherine Barthelmess, death records for Catherine, and a citizenship certificate for Cort Hansen. Incoming Correspondence primarily regards family history and the writing of his father's biography. Outgoing Correspondence is to Catherine Barthelmess and Cort Hansen. The Writings series includes "Casey's Autobiography" and "Shadow Catcher on an Army Mule," the latter became Photographer on an Army Mule. The Miscellany series includes lists of men on the LO Ranch and photographs used in "Thirty Years in the Army." The Clippings are primarily letters to the editor authored by Casey Barthelmess and others regarding life in the Miles City area. The Christian Barthelmess subgroup includes Outgoing Correspondence (1878, 1890), Writings (undated), and Miscellany (1898, circa 1901). The Outgoing Correspondence is written in German to an unknown recipient. The Writings series consists of articles for "Der Westen"--a German language newspaper in Chicago--regarding Navaho Indian ceremonies. The Miscellany series includes a commission certificate from the U.S. Army, and sheet music used by Barthelmess to teach and conduct the Second Infantry U.S. Band at Fort Keogh.