Summary: One of the most intriguing mysteries of pre-historic North America is the 10,000 ancient copper mines found in Northern Michigan, U.S.A. They were worked by unknown peoples between 3000 and 800 BC, with the most productive times being from 2000 to 1200 BC. Over 500,000 tons of copper were extracted from the mines during this period. It is not known for certain who worked the mines or where this copper output went. Archaeology to date has demonstrated that the Indians in North America used only a small portion of that output for their own use. The author believes that some of the excess copper was traded down the Mississippi as far as Meso-America, but that a large amount was shipped to the Mediterranean Basin between 1800 BC and 1200 BC, where there was a large shortage of the valuable metal. This article discusses this and the probable trade route.