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...

Abstract Collection, 1848-1988, of the Quincy Mining Company of Hancock, Michigan. Documents the development of the company from its humble start in 1846 through the cessation of underground mining in 1931 and the sale and disbursement of its Michigan properties in the 1970s and 1980s. 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...