The Round Island Channel is a navigable Lake Huron waterway located between Mackinac Island and Round Island in the Straits of Mackinac. It forms a key link in the lake freighter route between Lake Superior and Lake Michigan, on which millions of tons of taconite iron ore are shipped annually. The channel also provides access to the harbor of Mackinac Island, Michigan, and is used by commercial ferryboats delivering passengers to the small island city.