Thomas H. Irvine (1845-1926) was sheriff of Custer and Ravalli counties and U.S. deputy marshal. Papers (1879-1926) include correspondence, personal diaries, lists of wanted criminals, court papers, and account books. There are also several reminiscences on "Big Nose George" Parrott, the Battle of the Little Big Horn, the Kansas Jayhawkers, and Irvine's journey across the plains (1864)