This collection consists of records (1876-1974) of the Anaconda Copper Mining Company and contains correspondence, court papers, financial and production records, legal documents, organizational records, subject files, and other materials for the Anaconda Copper Mining Company and many of its predecessor and subsidiary companies and departments. Among the major subgroups are General Office; Big Blackfoot Milling Company; Bitter Root Development Company; Boston and Montana Consolidated Copper and Silver Mining Company; Colorado Smelting and Mining Company; Diamond Coal and Coke Company; Parrot Silver and Copper Company; Reduction Department (Anaconda); Silver Bow Club; Trenton Mining and Development Company; Tuttle Manufacturing and Supply Company; and Washoe Copper Company. In addition, there are more than 100 smaller subgroups.
Anton M. Holter (1831-1921) was a pioneer Helena, Montana, lumberman and founder of the A.M. Holter Hardware Company. Papers (1831-1921) include correspondence, and organizational and financial records relating to mining, agriculture, lumber, real estate, and oil interests of three generations of the family, headed successively by Anton M. Holter, Norman B. Holter, and Norman J. "Jeff" Holter. Many of the enterprises were in partnership with Samuel T. Hauser. Interests include the A.M. Holter Hardware Company; Holter Realty; Holter Research Foundation; Judith Farms; Montana Flour Mills; and the Helena and Frisco, Helena and Victor, the Maginnis mining companies, and many others.