Which Great Lake is entirely within the United States?

Lake Michigan is the only Great Lake located entirely within the United States.

Its shoreline is divided among Michigan, Wisconsin, Illinois, and Indiana, but no part of the lake lies in Canada. The other four Great Lakes all form part of the international boundary between the United States and Canada.

Lake Michigan is the third-largest Great Lake by surface area, covering roughly 22,300 square miles, and it reaches a maximum depth of about 923 feet. Major cities on its shores include Chicago, Milwaukee, and Green Bay.

A geographical wrinkle is its connection with Lake Huron through the Straits of Mackinac. Because the two lakes have the same water level and are hydrologically connected, scientists sometimes discuss them as the single Lake Michigan–Huron system. They are nevertheless conventionally counted as two Great Lakes, and only Michigan is wholly within U.S. borders.