In the summer of 1952, 13-year-old Donald Baldwin was dig­­ging around in an old gravel quarry near Oconto, Wisconsin, when he unearthed a pile of human bones. Thankfully, archaeologists were called to the scene rather than the local police, as young Donald had found an ancient burial ground. The skeletons, buried amid copper artifacts, turned out to be the earliest evidence of an ex­tensive, ancient trading culture based heavily on copper mined on the Keweenaw Peninsula and Isle Royale, along the shores of Lake Superior.