The records of the Tamarack & Custer Mining Company span the years 1907 to 1948, with the bulk of the material covering the years 1912 to 1947. Included are minutes, bylaws, annual reports and other documents relating to the meetings of directors and stockholders, correspondence and other records detailing the operation of the company, stock records, financial records, and information on ore shipments and production, material concerning supplies and equipment, personnel and payroll information, and insurance and tax material.

Related materials can be found in the records of the Tamarack & Chesapeak, the Custer Consolidated and Hercules Mining Companies, and the papers of John H. Wourms.