Collection, 1855-1973, of the Calumet and Hecla Mining Companies of Michigan's Keweenaw Peninsula. Includes corporate records, administrative correspondence, financial and legal documentation, employment and medical records, property and miners’ housing records, as well as operational records from the company’s underground, surface, stamp mill, reclamation, railroad, and smelting operations. Also includes records of numerous subsidiary and related companies operating in the Michigan copper district and other regions throughout North America. Although the Calumet and Hecla Mining Companies Collection often lacks the depth of specific detail evident in other mining company collections at the Michigan Technological University Archives and Copper Country Historical Collections, it provides comprehensive coverage of Calumet and Hecla’s diverse corporate activity during its century of operations. It contains great detail on the buildings, equipment, technologies, ancillary industries, and communities created to mine and treat the copper ore, and provides surprisingly comprehensive coverage of the workforce employed the company.

Arranged in 12 series with 3 appendices: 1. Calumet Mining Co. Records, 1864-1871. 2. Hecla Mining Co. Records, 1864-1871. 3. Calumet and Hecla Corporate Records, 1871-1969. 4. Administrative Records, 1866-1970. 5. Financial/ Legal Records, 1866-1972. 6. Departmental Records, 1858-1969. 7. Divisional Records, 1902-1968. 8. Subsidiary and Related Companies, 1855-1972. 9. Operational Records, 1864-1973. 10. Workforce Records, 1870-1971. 11. Property Records, 1864-1972. 12. Community Records, 1869-1969. Appendix 1. Corporate Offices. Appendix 2. Chronological List of Officers and Executives. Appendix 3. Alphabetical List of Officers and Executives.