Four States Border Lake Michigan: Illinois, Indiana, Michigan, and Wisconsin

Lake Michigan is the only Great Lake entirely within the United States. Its 1,640-mile shoreline touches four states:

• Illinois – Southwest shore (Chicago, Waukegan, Indiana Dunes).
• Indiana – Southern tip (Gary, Indiana Dunes National Park).
• Michigan – Entire eastern shore (Upper & Lower Peninsulas; Sleeping Bear Dunes, Mackinac Island).
• Wisconsin – Western shore (Milwaukee, Green Bay, Door County).

Lake Michigan connects to Lake Huron via the Straits of Mackinac (hydrologically one lake). Major ports: Chicago, Milwaukee, Green Bay. The lake supports shipping, fisheries, recreation, and drinking water for 12+ million people.