In Michigan, copper mining became an important industry in the 19th and early 20th centuries. Its rise marked the start of copper mining as a major industry in the United States.

Within the state of Michigan, copper is found almost exclusively in the western portion of the Upper Peninsula, in an area known as the Copper Country. The Copper Country is highly unusual among copper-mining districts, because copper is predominantly found in the form of pure copper metal (native copper) rather than the copper oxides or copper sulfides that form the copper ore at almost every other copper-mining district. The copper deposits occur in rocks of Precambrian age, in a thick sequence of northwest-dipping sandstones, conglomerates, ash beds, and flood basalts associated with the Keweenawan Rift.

The native copper deposits originate in fissures, steeply dipping veins or in the amygdaloid top portion of the Portage Lake Lava Series lava tops and conglomerate beds. This series of lava "is at least 15,000 feet thick in the Michigan copper district" and consists of "several hundred flood basalt flows." The district rocks are Precambrian in age and belong to the Keweenawan Series. The first six years of mining exploited the fissure deposits, then gave way to the amygdaloidal deposits.

Although native copper was the dominant ore mineral, chalcocite (copper sulfide) was sometimes present, and, especially in the Mohawk mine, copper arsenide minerals such as mohawkite and domeykite. Gangue minerals included calcite, quartz, epidote, chlorite, and various zeolites. A number of copper mines also contained a notable amount of silver, both in native form and naturally alloyed with the copper. Halfbreed is the term for an ore sample that contains the pure copper and pure silver in the same piece of rock; it is only found in the native copper deposits of the Upper Peninsula of Michigan.

Native Americans were the first to mine and work the copper of Lake Superior and the Keweenaw Peninsula of northern Michigan between 5000 BCE and 1200 BCE. The natives used this copper to produce tools. Archaeological expeditions in the Keweenaw Peninsula and Isle Royale revealed the existence of copper producing pits and hammering stones which were used to work the copper. Some authors have suggested that as much as 1.5 billion pounds of copper was extracted during this period, but some archaeologists consider such high figures as "ill-constructed estimates" and that the actual figure is unknown. Archaeologist Susan Martin wrote that "The competent excavation of many prehistoric archaeological sites in the Lake Superior basin reveals the continuous use of copper throughout the prehistoric time range, in association with all of the other items of material culture (projectile points, pottery and the like) that are without a doubt the products of native technologies. Many of these sites have been dated reliably by radiocarbon means.... Clearly, copper-working continues up until the years of aboriginal contact with seventeenth-century Europeans."

By the time the first European explorers arrived, the area was the home of the Ojibwe people, who did not mine copper. According to Ojibwe traditions, they had much earlier supplanted the original miners. The first written account of copper in Michigan was given by French missionary Claude Allouez in 1667. He noted that Indians of the Lake Superior region prized copper nuggets that they found there. Indians guided missionary Claude Dablon to the Ontonagon Boulder, a 1.5-ton piece of native copper along the Ontonagon River. When American prospectors arrived in the 1840s, pieces of copper were found in streams or on the ground.

Douglass Houghton's 1841 copper report, followed by the Treaty of La Pointe in 1843, the publicity of the Ontonagon Boulder back east, and a federal mineral land office at Copper Harbor kicked off the mine rush.

The copper pits abandoned by Native Americans led early miners to most of the first successful mines. "All the principal ore deposits were thus known before 1900, and each was discovered in exposures at or close to grass roots."