The Straits of Mackinac is a narrow strip of water that connects two of the Great Lakes, Lake Michigan and Lake Huron. It also separates the Lower Peninsula of Michigan from the Upper Peninsula of Michigan.
Just under five miles wide at its narrowest point; there it is spanned by the Mackinac Bridge, one of the longest suspension bridges on the planet.
It is a very busy shipping lane, spring to early winter. With the advent of icebreakers, huge tankers still navigate through the Straits of Mackinac in the dead of winter, even though most of the surrounding waters are frozen solid.
The Straits of Mackinac includes four islands; the populated islands of Bois Blanc and Mackinac, and two uninhabited islands, Round and St. Helena.
In addition to ferries, Bois Blanc Island and Mackinac Island can be reached by private boat; and in the winter, by snowmobile.