The total span of the Mackinac Bridge, including approaches, is 5 miles. The length of the main span is 8,614 feet. The total length of wires in the main cables is 42,000 miles. The height of the towers above the water is 552 feet and the maximum depth of towers beneath the water is 210 feet. The bridge opened on November 1, 1957 and cost $99,800,000 to build.