The Mackinac Bridge is a suspension bridge spanning the Straits of Mackinac, connecting the Upper and Lower peninsulas of the U.S. state of Michigan. Opened in 1957, the 26,372-foot-long bridge is the world's 24th-longest main span and the longest suspension bridge between anchorages in the Western Hemisphere. Total length: 26,372' (or 4.8 miles) Longest span: 3,799' Construction started: May 7, 1954 Opened: November 1, 1957 Height: 552' Clearance below: 155'