Copper mining on Isle Royale is no recent thing--in fact it has spanned a period of more than 4,500 years. When man first arrived in the New World, perhaps 15,000 to 20,000 years ago, Isle Royale was still covered with thick glacial ice. By the time the ice receded from the Lake Superior Basin and Isle Royale rose above the waters of the lake about 10,000 years ago, Indians already had begun to occupy parts of the Upper Great Lakes.
It will never be known when the first man ventured out across Lake Superior to Isle Royale, but by 2,500 BCE or shortly thereafter, North American Indians began to exploit the pure copper deposits that were exposed on the surface of the island. Archeologists feel that the Indians may not have deliberately prospected for copper, at least at first, but in the course of their travels about the island, they would watch for nuggets and veins of the bright metal. Eventually a method was developed of extracting the raw copper from the bedrock by beating it free with rounded, hand-held beach cobbles. Thus, numerous pits were dug in the most productive locations on the island, especially along Minong Ridge. Recent archeological excavations have uncoverd large numbers of hammer-stones from the ancient mines which are now filled in by soil and covered with vegetation.
More than 1,000 pits attributed to the Indians have been located on Isle Royale, but since the activity covered a period of at least 1,500 years, there is no basis for suggesting any highly organized efforts to procure the copper. Rather, the mining probably was pursued in the course of an annual round of hunting, fishing, and collecting berries and plants. The copper itself was cold-hammered into knives, points, and a variety of ornaments, either on Isle Royale or taken to the mainland and then worked. Artifacts of Lake Superior copper ultimately made their way to the southern Lake States and New England. Unfortunately, very little is known about the way of life of these earliest miners, since no habitation sites from the mining period have been located on Isle Royale.