Great Lakes form a single, naturally interconnected body of fresh water, within the Great Lakes Basin. They form a chain connecting the east-central interior of North America to the Atlantic Ocean. From the interior to the outlet at the Saint Lawrence River, water flows from Superior to Huron and Michigan, southward to Erie, and finally northward to Lake Ontario. The lakes drain a large watershed via many rivers, and are studded with approximately 35,000 islands. There are also several thousand smaller lakes, often called "inland lakes," within the basin. The surface area of the five primary lakes combined is roughly equal to
Great Lakes region Hudson, Mohawk and Susquehanna form an arc of watersheds east to The Atlantic. The Great Lakes region, as distinct from the Great Lakes Basin, defines a unit of sub-national political entities defined by the U.S. states and the Canadian Province of Ontario encompassing the Great Lakes watershed, and the states and Province bordering one or more of the Great Lakes. Prior to European settlement, Iroquoian people lived around Lakes Erie and Ontario, Algonquian peoples around most of the rest, and a variety of other indigenous nation-peoples including the Lakotan, Ojibwa, Illinois, Pottawatmie, Huron, Shawnee, Erie, Fox, Miami, Crow and Ho-Chunk