From the Associated Press — Images from an underwater vehicle seem to reveal stone patterns on the bottom of the Straits of Mackinac in northern Michigan. An expert says it’s possible evidence of Native American artifacts from thousands of years ago. It also could add a new wrinkle to Enbridge’s proposed pipeline tunnel. A group of amateur explorers raised money to look at Enbridge’s pipeline on the lake bottom. The Detroit Free Press says sonar shows what appears to be stones in a half-circle. Andrea Pierce of Ypsilanti says it’s “really amazing.” The Great Lakes weren’t always around. Glaciers cut deep gorges into the earth, which then filled with water over thousands of years.