Mackinaw City, Michigan in the context of Fort Michilimackinac

The Mackinac Bridge (/ˈmækənɔː/ MAK-ə-naw; also referred to as the Mighty Mac or Big Mac) is a suspension bridge that connects the Upper and Lower peninsulas of the U.S. state of Michigan. It spans the Straits of Mackinac, a body of water connecting Lake Michigan and Lake Huron, two of the Great Lakes. Opened in 1957, the 26,372-foot-long (4.995 mi; 8.038 km) bridge is the world's 29th-longest main span and is the longest suspension bridge between anchorages in the Western Hemisphere. The Mackinac Bridge is part of Interstate 75 (I-75) and carries the Lake Michigan and Huron components of the Great Lakes Circle Tour across the straits; it is also a segment of the U.S. North Country National Scenic Trail. The bridge connects the city of St. Ignace to the north with the village of Mackinaw City to the south.

Envisioned since the 1880s, the bridge was designed by the engineer David B. Steinman and completed in 1957 only after many decades of struggles to begin construction. The bridge has since become an iconic symbol of the state of Michigan.

St. Ignace (/ˈɪɡnəs/ IG-nəss) is a city in the U.S. state of Michigan and the county seat of Mackinac County. The city had a population of 2,306 at the 2020 census. St. Ignace Township is located just to the north of the city; the two are administered separately.

St. Ignace is located along Lake Huron in the Upper Peninsula on the northern side of the Straits of Mackinac. The city serves as a gateway to the state's Upper Peninsula for travelers coming from the Lower Peninsula, as the city is at the north end of the Mackinac Bridge, opposite Mackinaw City. It has one of two ports which provide ferry service to nearby Mackinac Island.

U.S. Route 23 or U.S. Highway 23 (US 23) is a major north–south United States Numbered Highway between Jacksonville, Florida, and Mackinaw City, Michigan. It is an original 1926 route which originally reached only as far south as Portsmouth, Ohio, and has since been extended. It was formerly part of the major highway known as the Dixie Highway. The highway's southern terminus is in Jacksonville, Florida, at US 1/US 17. The northern terminus is at Interstate 75 (I-75) in Mackinaw City, Michigan.