A group of Native American tribespeople, who were cruising the Straits of Mackinac to examine oil and natural gas pipelines, may have accidentally stumbled on proof of a 100,00-year-old Ice Age society. The group, all nonscientists, found stones arranged in unnatural patterns when they sent a remote-operated vehicle down to the bottom of the lake. The rock formations need further evaluation but it potentially confirms that humans roamed the area when the Straits was last above water—around the end of the last Ice Age. “We didn’t expect to find this—it was really just amazing,” said Andrea Pierce, a 56-year-old Ypsilanti resident and citizen of the Little Traverse Bay Bands of Odawa Indians.