Although the railroads shown on this map did not yet exist, the map documents the natural resources that provoked much interest in the Upper Great Lakes region.
Based on U.S. Land Survey records by W.R. Wood, the map shows the extent of copper and iron ore in Michigan’s Upper Peninsula and in northern Wisconsin. By the 1840s, the rich deposits of copper were being mined in Michigan’s Keweenaw Peninsula. This mining activity resulted in Michigan’s Upper Peninsula being more extensively surveyed at this time than northern Wisconsin.
Extensive mining of iron ore in the various ranges of Michigan’s Upper Peninsula and northern Wisconsin began between the 1850s and 1880s as railroads provided transportation to ports along Lakes Michigan and Superior. In 1855, completion of a canal at Sault Ste. Marie also permitted inexpensive shipment of iron ore from Lake Superior ports to large smelters along southern Lake Erie.