The Mackinac Bridge (/ˈmækɨnɔː/ MAK-in-aw) is a suspension bridge spanning the Straits of Mackinac to connect the Upper and Lower peninsula of the U.S. state of Michigan. Opened in 1957, the 8,614-foot (2,626 m) bridge (familiarly known as "Big Mac" and "Mighty Mac") is the world's 16th-longest in total suspension and the longest suspension bridge between anchorages in the Western hemisphere. The Mackinac Bridge carries Interstate 75 and the Lakes Michigan and Huron components of the Great Lakes Circle Tours across the straits and connects the city of St.