Great Bridges Codexery

Mackinac Bridge

Longest suspension bridge between anchorages in the Western Hemisphere.

Mackinac Bridge

via Wikipedia: Mackinac Bridge · see source

The Mackinac Bridge—often called the Mighty Mac or Big Mac—is a suspension bridge in Michigan linking the state's Upper and Lower Peninsulas. It crosses the Straits of Mackinac, the waterway that joins Lake Michigan and Lake Huron. When it opened in 1957, its 26,372-foot length (roughly 5 miles) made it the longest suspension bridge between anchorages in the world. Today it remains the longest such span in the Western Hemisphere, though longer ones—like Japan's Akashi Kaikyō Bridge—have since been built elsewhere. Its main span stretches 3,800 feet, ranking it as the third-longest suspension span in the United States and 32nd longest globally. The bridge carries Interstate 75, forms part of the Great Lakes Circle Tour, and is also a segment of the North Country National Scenic Trail. It connects St. Ignace to the north with Mackinaw City to the south.

People first imagined a bridge across the straits in the 1880s, inspired by the Brooklyn Bridge. In 1884, a St. Ignace store owner ran an ad featuring a drawing of the Brooklyn Bridge with the caption “Proposed bridge across the Straits of Mackinac.” The Michigan Legislature discussed the idea as early as that decade, especially after Mackinac National Park was created on Mackinac Island in 1875. In July 1888, Cornelius Vanderbilt II proposed a bridge similar to the one then being built over Scotland's Firth of Forth, hoping to boost regional commerce and extend the Grand Hotel's season. But decades passed without action. In 1920, the state highway commissioner suggested a floating tunnel. Later, engineer C. E. Fowler proposed a 17-mile chain of causeways and bridges from Cheboygan to St. Ignace, using Bois Blanc, Round, and Mackinac islands.

By 1923, the state legislature ordered a ferry service across the straits. As traffic grew, so did support for a bridge. Former governor Chase Osborn argued that Michigan was unifying itself and that ferries were too clumsy and inadequate for the growing route. In 1928, Governor Fred W. Green ordered a feasibility study, which estimated the cost at $30 million. In 1934, the legislature created the Mackinac Straits Bridge Authority to explore construction and funding. The Authority tried twice during the Great Depression to get federal money, but Congress never appropriated funds, despite endorsements from the Army Corps of Engineers and President Franklin D. Roosevelt. Between 1936 and 1940, the Authority chose a route and conducted geological borings. The bridge was finally built in 1957, designed by engineer David B. Steinman, after decades of struggle. It replaced the ferry service, which at its peak operated nine boats carrying up to 9,000 vehicles daily, with backups sometimes stretching 16 miles. The bridge has since become a well-known symbol of Michigan.

opened
November 1, 1957
total length
26,372 feet (4.995 mi; 8.038 km)
main span length
3,800 feet (1,158 m)
design engineer
David B. Steinman
construction cost
$100 million
location
Straits of Mackinac, Michigan, United States
type
Suspension bridge

Verified Timeline

1875188418881920192319281934193619401947195019511952195319541957195819982007

Lore & Background

The concept of a bridge across the Straits of Mackinac was imagined as early as the 1880s, following the opening of the Brooklyn Bridge. In 1884, a store owner in St. Ignace published a newspaper advertisement with an artist's conception of the Brooklyn Bridge captioned 'Proposed bridge across the Straits of Mackinac.' At a July 1888 meeting of the board of directors of the Grand Hotel on Mackinac Island, Cornelius Vanderbilt II proposed a bridge of a design similar to the one then under construction across the Firth of Forth in Scotland. Decades passed with no formal action; in 1920, the Michigan state highway commissioner advocated a floating tunnel, and later C. E. Fowler of New York City put forth a plan for causeways and bridges using Bois Blanc, Round, and Mackinac islands as intermediate steps. Formal planning began in 1923 when the state legislature ordered the State Highway Department to establish ferry service across the strait. By 1928, the ferry service had become so popular and expensive that Governor Fred W. Green ordered a feasibility study, which estimated the cost at $30 million. In 1934, the Michigan Legislature created the Mackinac Straits Bridge Authority to explore construction and funding. The Authority twice attempted to obtain federal funds during the Great Depression but was unsuccessful. Between 1936 and 1940, a route was selected and borings were made for geological study. Work was put on hold due to World War II, and the Authority was abolished in 1947. A new Mackinac Bridge Authority was created in 1950, and engineers were retained. In January 1951, a report led the state legislature to authorize $85 million in bonds on April 30, 1952, though a weak bond market delayed issuance until 1953. David B. Steinman was appointed design engineer in January 1953. Civil engineer Abul Hasnat did the preliminary plans. Construction began on May 7, 1954, under two major contracts: Merritt-Chapman and Scott Corporation for substructure work ($25.7 million) and American Bridge Division of United States Steel Corporation for the steel superstructure (over $44 million). Construction took three and a half years (four summers, no winter construction) at a total cost of $100 million and the lives of five workers. Contrary to popular belief, none are entombed in the bridge. The bridge opened to traffic on schedule on November 1, 1957, and ferry service ceased the same day. It was formally dedicated on June 25, 1958.

Reader's Guide

The Mackinac Bridge is a significant infrastructure achievement that permanently linked Michigan's Upper and Lower Peninsulas, replacing a ferry system that could cause traffic backups up to 16 miles. At its opening, it was the world's longest suspension bridge between two anchorages, and it remains the longest such bridge in the Western Hemisphere. The bridge carries Interstate 75 and is part of the Great Lakes Circle Tour and the North Country National Scenic Trail. Its construction overcame decades of political, financial, and engineering challenges, including failed attempts at federal funding during the Great Depression and a delay due to World War II. The bridge has become a well-known symbol of the state of Michigan. It officially achieved its 100 millionth crossing on June 25, 1998, exactly 40 years after its dedication. The 50th anniversary of its opening was celebrated on November 1, 2007. The bridge also initiated the tradition of the governor leading the Mackinac Bridge Walk across it every Labor Day, started by Governor G. Mennen Williams, who was the first to pay the toll and rode the last ferry trip about an hour later.

Did You Know?

Common Misconceptions (Editorial)

- A common misconception is that five workers who died during construction are entombed in the bridge. The facts confirm that while five lives were lost, contrary to popular belief, none are entombed in the bridge. - Another misconception is that the bridge was only a recent or simple idea, but the concept was first imagined in the 1880s, with serious planning beginning in 1923 and formal proposals dating to the 1920s and 1930s.

Why It Matters (Editorial)

The Mackinac Bridge endures as a symbol of Michigan’s unity, physically linking the state’s two peninsulas and replacing a costly and unreliable ferry system with a reliable roadway. Its construction—completed on budget and on schedule despite immense engineering challenges—represents a triumph of mid-20th-century infrastructure and continues to carry Interstate 75 and millions of travelers each year.

Frequently Asked Questions

What is the Mackinac Bridge and where is it located?

It is a suspension bridge spanning the Straits of Mackinac in Michigan, physically linking the state's Upper and Lower peninsulas. Locals often call it the Mighty Mac or Big Mac.

How long is the Mackinac Bridge?

The full structure stretches about 26,372 feet (roughly five miles), with a main span of 3,800 feet between its two towers.

Who designed the Mackinac Bridge?

The design engineer was David B. Steinman, a prominent structural engineer known for several major suspension bridges.

When did the Mackinac Bridge open to traffic?

It officially opened on November 1, 1957, after a construction project that cost around $100 million at the time.

Why is the Mackinac Bridge considered significant?

It holds the record as the longest suspension bridge between anchorages in the Western Hemisphere. It also serves as a critical link on Interstate 75, connecting the two Great Lakes regions of Michigan.

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