Lake Michigan is one of the five Great Lakes of North America and the only one located entirely within the United States. The other four Great Lakes are shared by the U.S. and Canada. It is the second-largest of the Great Lakes by volume and the third-largest by surface area, after Lake Superior and Lake Huron. To the east, its basin is conjoined with that of Lake Huron through the wide Straits of Mackinac, giving it the same surface elevation as its easterly counterpart; the two are technically a single lake.