Straits of Mackinac

The Straits of Mackinac are a narrow waterway in the U.S. state of Michigan that connects Lake Michigan and Lake Huron. They separate Michigan’s Upper and Lower Peninsulas and are spanned at their narrowest point by the Mackinac Bridge. Although usually treated as two lakes, the straits are so broad and interconnected that the water body is sometimes studied as Lake Michigan–Huron.

The straits are an important shipping route for the Great Lakes, carrying raw materials and manufactured goods. They are shallow enough to freeze in winter, so navigation is maintained by icebreakers, including the USCGC *Mackinaw*. Passenger ferries connect the mainland with Mackinac Island, while car ferries also serve Bois Blanc Island. The eastern side of the straits is marked by Bois Blanc Island, Mackinac Island, and Round Island.

The region was long used by Native peoples and later became a major fur trade corridor. The name derives from Mackinac Island, itself adapted from the Ojibwe Mitchimakinak, meaning “Big Turtle.” Early French and British presence included St. Ignace, site of a mission founded in 1671, Fort Michilimackinac at Mackinaw City, and Fort Mackinac on Mackinac Island.

Today, the straits are closely monitored by the United States Coast Guard and include the state-managed Straits of Mackinac Shipwreck Preserve. They also remain the focus of environmental concern because Enbridge Line 5 crosses beneath the straits, prompting debate over pipeline safety and possible replacement with a tunnel.