Superior, Lake

Superior, Lake, east central North America, largest body of fresh water in the world by area, bounded on the north and east by Ontario, on the south by Michigan and Wisconsin, and on the north-west by Minnesota. The deepest and westernmost of the five Great Lakes, it is 560 km (350 mi) long and has a surface area of about 82,100 sq km (31,700 sq mi); about two-thirds of the lake is in the United States.

Lake Superior has an irregular coastline, with a number of large bays; Keweenaw Peninsula, in Michigan, projects far into the lake. The northern lakeshore is fringed by bold, rocky cliffs, some rising 300 m (1,000 ft) above the water surface. Near Munising, Michigan, on the south-eastern shore, are the Pictured Rocks, multicoloured sandstone cliffs, 15 to 90 m (50 to 300 ft) high, which in many places present fantastic forms. Several large forests border the lake, which receives many small streams, such as the Nipigon River, from the north, and the St Louis River, from the west. The lake drains into Lake Huron, to the south-east, through the St Marys River, which is navigable via the Sault Sainte Marie Canals. Lake Superior has several large islands, notable among them St Ignace Island and Michipicoten Island, Ontario; Isle Royale, Michigan; and the Apostle Islands, Wisconsin.

The land near the lake is rich in minerals, principally iron ore (haematite and taconite) and copper, nickel, and silver ores. These minerals, plus grain produced in the Prairie provinces of Canada and forest products, are shipped east via Superior and the rest of the Great Lakes-St Lawrence Seaway system. Lake Superior very rarely freezes over, but ice along its shores closes its ports from December to mid-April. Major lakeports include Thunder Bay and Michipicoten Harbour, Ontario; Marquette and Copper Harbor, Michigan; Ashland, Wisconsin; Superior, Wisconsin-Duluth, Minnesota; and Two Harbors and Taconite Harbour, Minnesota. The first European to sight the lake was probably Étienne Brûlé, the French explorer, in 1622.