This collection consists of personal records and four subgroups. The personal records include general correspondence (1886-1890) relating to various business partners including Massena Bullard, W.A. Clark, and T.H. Kleinschmidt; financial records (1886-1889) including check stubs and scattered invoices and receipts from Helena area businesses; and a mining claim (1886) for Grand Central Quartz Lode.

The Broadway Street Railway Company Records subgroup includes general correspondence (1888-1890); financial records (1887-1890) including invoices, receipts, payroll and construction costs; and legal documents (1883, 1889-1891) including agreements and licenses.

The Homestake Mining Company Records consist of correspondence (1889); financial records (1888-1889) including assays, bills, a journal, stock purchases, and payroll and legal documents (1889-1890) including abstract of title and development statements.

The Neihart Tunnel and Mining Company Records consist of correspondence (1886) with investors and contractors; court papers (1886) testimony of C.D. Ladd; financial records (1886) including receipts and bids; legal documents (1886); minutes (1886) scattered; and miscellany.

The Wells, Fargo & Company Records include general correspondence (1885-1886) between Carter and customers; interoffice correspondence (1885-1887) between Carter and other agents across the country; financial records (1885-1886) including a bank book, cancelled checks and receipts; and subject files (1885-1886) relating to a stage robbery; and miscellany (1886) including appointment books and notes regarding assignments and deliveries.