- Straits of, a strait between the peninsulas of Upper Michigan and Lower Michigan, connecting lakes Huron and Michigan.
- Also Mackinac Island. an island in Lake Huron at the entrance of this strait. 517; 3 miles (5 km) long.
- a wooded island in N Michigan, in the Straits of Mackinac (a channel between the lower and upper peninsulas of Michigan): an ancient Indian burial ground; state park. Length: 5 km (3 miles)