Abstract 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...