The Keweenaw Peninsula is a peninsula of the U.S. state of Michigan. Part of the greater landmass of the Upper Peninsula, the Keweenaw Peninsula projects about 65 miles (105 km) northeasterly into Lake Superior, forming Keweenaw Bay. The peninsula is part of Michigan's Copper Country region, as the region was home to the first major copper mining boom in the United States. Copper mining was active in this region from the 1840s to the 1960s.