Ep 5 - Ancient Mysteries of Isle Royale

Twenty miles off Minnesota’s North Shore in Lake Superior lies Isle Royale. It’s a lonely, rarely visited place, even though part of America’s National Park system. Now, new research is revealing that a mysterious civilization began 9,000 years ago on that island and started a mining operation that thrived for four millennia. We still don’t know exactly who those people were or why they were there, working so hard, for 4,000 years.