The Douglas Mine and Concentrator operated in Granite County, Montana from 1964-1968 under the ownership of the Montana Phosphate Products Company and later Cominco American, Inc. The records contain material related to the development, operation and dismantling of the mine and concentrator, as well as several maps and engineering drawings illustrating the Douglas Operation and other nearby mines owned by these same companies.
The collection contains family papers and records related to the business investments of Marcus Daly of Montana, copper magnate, businessman, and politician. The collection primarily consists of family estate papers and business records of the Bitterroot Stock Farm from the 1880s to 1990s. The daily operational activities of the Bitterroot Stock Farm, including ranching, horse breeding, and agricultural activities, are especially well documented. The records of the Valley Mercantile of Hamilton are also quite extensive and detail the financial activities of the company. The collection also contains records related to the business investments of Marcus Daly and his heirs in mining industries, water irrigation projects, retail businesses and real estate ventures from the 1880s to the 1990s. Materials include correspondence, financial records, reports, minutes, legal documents and aerial maps of the family properties.