Calumet & Hecla, Inc., was the most successful corporation to have mined native copper in Michigan's Upper Peninsula. Through nearly a century of mining activity, the company produced in excess of 4.5 billion pounds of refined copper and issued over $200 million in shareholder dividends. Unlike many of its competitors along the Keweenaw Peninsula, Calumet and Hecla successfully expanded its operations over several separate mineral bodies, developed capital-intensive ancillary industrial facilities, explored diversified non-mining enterprises, and remained a significant mining corporation at the national and international level well past the district's most productive era.
From the description of Calumet and Hecla Mining Companies Drawings Collection, 1871-1970. (Michigan Technological University). WorldCat record id: 759106034
