Swimming Drone Explores Underwater Mountain In Lake SuperiorOctober 4, 2025Jessica Mathews / Associated Press / News@whmi.comKnown to some as the “Freshwater Everest” - if you want to explore this mountain, you don’t go up, you go down. In the middle of Lake Superior, near the boundary between Canadian and US waters, sits the Superior Shoal, a mountain that’s completely underwater. Others include Stannard Rock, a reef in Lake Superior north of Marquette; a knoll outside Tobermory, Ontario in Lake Huron; and Midlake Reef in Lake Michigan, between Muskegon and Milwaukee. And it’s not the only “Superior Shoal.” There’s another located in the St. Lawrence River off the shore of New York. But Drebert and Melnick believe the Superior Shoal in Lake Michigan is the largest known underwater mountain in fresh water.