Did you know there’s a 9,000-year-old mystery beneath Lake Michigan? In 2007, researchers discovered an underwater stone formation in Grand Traverse Bay, often called “Michigan’s Stonehenge.” Lying 40 feet below the surface, the stones are arranged in a long, organized pattern, possibly used for hunting, ceremonies, or as an ancient calendar.One stone even has what appears to be a mastodon carving, suggesting it was created when these prehistoric giants still roamed North America. While it’s not