Centennial #6 was the last of the mines near Calumet to be abandoned and allowed to fill with water. Why do the mines fill with water? This mine was a conglomerate ore body and it followed the dip deep into levels thousands of feet from the surface.
Mohawkite Nugget
Sketch of Cliff Mine, 1849 Michigan Tech Archives
Of course indigenous people mined copper on the Keweenaw and Isle Royale. The earliest of Michigan’s mechanized copper mines was the Cliff Mine, which got underway in a serious way in August 1845 when a vein on the greenstone cliff was followed into the cliff wall and it widened into a substantial copper mass. By 1848 there was mining fever here and many of the 49ers who were in the California gold rush of 1949 learned a lot about mining here under the Cliff. Read more in History of the Cliff Mine by Sean Gohman or in Michigan Geological Survey Bulletin #1.
