Papers, 1904-1911, of Walter G. Swart, a mining engineer associated with the American Zinc, Lead and Smelting Company. Includes correspondence between Swart and Calumet and Hecla Mining Company, as well as reports to stockholders for companies in Michigan's Keweenaw Peninsula, including Calumet and Hecla Mining Company, Osceola Consolidated Mining Company and Seneca Mining Company.