Lake Superior is a lake in central North America. The northernmost, westernmost, and highest of the Great Lakes, Lake Superior straddles the Canada–United States border with the Canadian province of Ontario to the north and east and the U.S. states of Minnesota to the west and Michigan and Wisconsin to the south. It is the largest freshwater lake in the world by surface area and the third-largest freshwater lake by volume. It drains into Lake Huron via St. Marys River, then through the lower Great Lakes to the St. Lawrence River and ultimately the Atlantic Ocean.