Mackinaw City in Cheboygan County, Michigan — The American Midwest (Great Lakes)
Building Mighty Mac
Mackinaw City Historical Pathway
The Mackinac Bridge is constructed of three segments – at each end is a post-supported truss bridge and in the center is a suspension bridge segment. This bridge was the longest suspension bridge in the world for decades after its construction. Today most of the longest are in China.
Mighty Mac is an engineering masterpiece designed to withstand crushing ice and winds up to 120 mph. It is also a construction triumph, built for $99.8 million between 1954 and 1957 – on time and within budget. The 4.5 million vehicles which safely cross the bridge each year pay tribute to its dedicated builders, the crews that overcame the harsh winters, and the winds of the Straits.
How the suspension part of the bridge works
Truss bridges, supported by posts, are far cheaper to build than suspension bridges. But the water in the Straits of Mackinac gets quite deep, up to 300 feet, and it was impractical to put posts that deep.
The engineers put an anchor block, or main supporting post, (shown in red below) at each edge of the deep water. Cables, propped up by two towers, were stretched between
The bridge designers determined the required height of the towers, how tall the towers should be, by calculating the bridge span and the desired height of the roadbed above the water. The roadbed is 149 feet minimum above the water to allow for the passage of freighters and tall ships.
Topics. This historical marker is listed in these topic lists: Bridges & Viaducts • Roads & Vehicles. A significant historical year for this entry is 1954.
Location. 45° 47.232′ N, 84° 43.664′ W. Marker is in Mackinaw City, Michigan, in Cheboygan County. Marker can be reached from North Huron Street. Marker is located in Alexander Henry Park, on the shore of Lake Huron, along the Mackinaw City Historical Pathway, looking north toward the bridge. Touch for map. Marker is in this post office area: Mackinaw City MI 49701, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Graveyard of the Deep (here, next to this marker); Crossroads of the Great Lakes (within shouting distance of this marker); Shipwrecks in the Straits (within shouting distance of this marker); Alexander Henry Park Kiosk (within shouting distance of this Alexander Henry 1739 - 1834 (within shouting distance of this marker); Fog Signal Station (about 400 feet away, measured in a direct line); Old Mackinac Point Lighthouse (about 500 feet away); Lighthouses of the Mackinac Straits (about 500 feet away). Touch for a list and map of all markers in Mackinaw City.
More about this marker. The Mackinac Bridge is five miles long and crosses the Straits of Mackinac, connecting the upper and lower peninsulas of Michigan. It is the longest suspension bridge in North America. The building of the Mackinac Bridge began in May 1954 and opened to traffic November 1, 1957. A dedication was held in June 1958, with Governor G. Mennen Williams attending.
Marker is part of the "Mackinaw City Historical Pathway" series
Related markers. Click here for a list of markers that are related to this marker.
Also see . . .
1. Building the Mackinac Bridge. Mackinac Bridge - The Mighty Mac entry:
After more than 70 years of dreams, with many different plans for bridging the Straits of Mackinac, ground breaking to build the Mackinac Bridge took place in St. Ignace on May 7, 1954 and Mackinaw City on May 8. The photos on this page are from slides taken by my father, Lester Stokes, who lived less than a block from the foot of the Mackinac Bridge in Mackinaw City, and worked on the State Dock which served the automobile ferries until November 1, 1957, when the Mackinac Bridge opened and ferry service was discontinued. (Submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida.)
2. History of the Bridge. Mackinac Bridge Authority entry:
The dedication of the Brooklyn Bridge in 1883 gave Mackinac Bridge backers encouragement. (Submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida.)
Credits. This page was last revised on January 31, 2021. It was originally submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida. This page has been viewed 129 times since then and 8 times this year. Photos: 1, 2, 3, 4. submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida. 5. submitted on October 17, 2019, by Joel Seewald of Madison Heights, Michigan. 6. submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida. • Bill Pfingsten was the editor who published this page.