This collection contains incoming and outgoing correspondence, financial records, legal documents, reports, and miscellany dealing with Cruse's various activities (1882-1914), including the Thomas Cruse Savings Bank and the N Bar Ranch. The collection also documents the Thomas Cruse Estate and the Thomas Cruse Mining and Development Company, which was formed from many of the Cruse holdings. Other subgroups represent key individuals active in the various Cruse organizations: Fred T. Cruse, Mamie T. Cruse, Richard Cruse, William J. Cruse, William Scallon, and William J. Sweeney. The collection documents mining activity in Montana (1879-1956), Montana banking (1887-1916), and Montana cattle and sheep ranching (1890-1913).