Keweenaw native copper (Delaware Mine)

Almost every copper district on Earth mines a compound. This one mined the metal itself.

The Copper Country covers Keweenaw, Houghton, Baraga and Ontonagon counties in Michigan's Upper Peninsula, plus part of Marquette County, and takes in Copper Island, Copper Harbor and Isle Royale. Copper mining ran here from 1845 into the late 1960s, with the White Pine mine carrying on until 1995. In its heyday, through the second half of the 19th century and the start of the 20th, this was the greatest copper-producing region in the world.

The ore is unusual. At almost every other copper district the metal arrives locked into compounds, mostly oxides and sulfides, and has to be smelted out. Here it was predominantly native copper, elemental metal sitting in the rock, which is why the region produced masses of pure copper rather than concentrate.

People worked it a very long time before industry did. Supporting the Old Copper complex, Native Americans were mining copper from small pits on this peninsula as early as 3000 BC, and artifacts made from that copper have turned up from Michigan through Wisconsin to Minnesota along the lake. Douglass Houghton, Michigan's state geologist in the mid-1800s, is the name attached to the rush that followed.

The mines also built one of the most unusual communities in the country. Michigan Technological University's archive project on immigration here, funded in part by the Michigan Humanities Council, argues that at the turn of the century the Keweenaw Peninsula was the most ethnically diverse place in Michigan and among the most diverse in the United States. The 1870 Federal Census recorded Houghton County at 57 per cent foreign-born, the third highest proportion in the country. Cornish, Finns, Croatians, Slovenes, Italians, Poles, Irish, Germans, French Canadians and Chinese all worked this rock.

Nothing in the mineshafts and rock piles says any of that on its own. Visit the archives as well as the pits.