Lake Superior islands include Madeline Island in the state of Wisconsin, Michipicoten Island in the province of Ontario, and Grand Island (the location of the Grand Island National Recreation Area) in the state of Michigan. The larger cities on Lake Superior include the twin ports of Duluth, Minnesota and Superior, Wisconsin; Thunder Bay, Ontario; Marquette, Michigan; and the twin cities of Sault Ste. Marie, Michigan, and Sault Ste. Marie, Ontario. Duluth-Superior, at the western end of Lake Superior, is the most inland point on the St. Lawrence Seaway and the most inland port in the world. Among the scenic places on the
Geology of Minnesota of the receding sea to form the Mesabi, Cuyuna, Vermilion, and Gunflint iron ranges from the center of the state north into Northwestern Ontario, Canada. These regions also showed the first signs of life as algae grew in the shallow waters. Over 1,100 mya, a rift formed and lava emerged from cracks along the edges of the rift valley. This Midcontinent Rift System extended from the lower peninsula of Michigan north to the current Lake Superior, southwest through the lake to the Duluth area, and south through eastern Minnesota down into what is now Kansas. The rifting stopped before the