The Frank A. Hadsell collection consists of various records about his social, business and political interests. Much of the collection is comprised of correspondence. Topics include county and state Republican party politics, agriculture (particularly sheep), efforts to split Fremont County, good roads movement, public lands, and efforts to get US Marshal appointment. Correspondents include F.E. Warren, C.D. Clark, F. Chatterton, B.B. Brook and Willis Van Devanter.

Of particular interest is the correspondence during the period Hadsell served as US Marshal for Wyoming (1899-1907). Included are letters and messages relative to the activities and pursuit of the Wild Bunch, including Butch Cassidy, The Sundance Kid and Kid Curry. Information relates to the Union Pacific train robberies at Wilcox and Tipton, the Great Northern train robbery at Wagner, Montana, and Winnemucca, Nevada, bank robber and other turn-of-the century incidents.

Also included are a letter from Bill Nye, dated January 19, 1880, about his view of how the Ute Indians should be dealt with, and a letter from James Averill to Hadsell, dated March 25, 1889, about payment of Averill's debts.