Mackinac Bridge

A giant bridge crosses the water.

It connects two pieces of land in Michigan. People used to take boats to cross.

The bridge opened in 1957. It is very long.

The bridge stays steady in high winds. It has a special road to help. This makes the bridge safe for cars. It is a famous symbol for the state.

The Mackinac Bridge is a huge suspension bridge.

It connects two parts of Michigan. These are the Upper and Lower peninsulas. The bridge spans the Straits of Mackinac. This is the water between Lake Michigan and Lake Huron.

Before the bridge, people used ferries to cross. Ferries are large boats that carry cars. In 1923, the state started a ferry service. By 1950, cars had to wait five hours for a boat!

The bridge finally opened on November 1, 1957. An engineer named David B. Steinman designed it. He wanted the bridge to stay steady in high winds. He used a stiffening truss to help. This is a strong frame that supports the road. He also used an open-grid roadway. This means there are gaps in the road. These gaps let air flow through. This helps the bridge stay still during storms.

The bridge is a famous symbol for Michigan. It is part of Interstate 75. People still pay a toll to cross it today.

The Mackinac Bridge is a famous suspension bridge in Michigan.

It connects the Upper and Lower peninsulas across the Straits of Mackinac. This water connects two Great Lakes, Lake Michigan and Lake Huron. People often call the bridge the "Mighty Mac" or the "Big Mac." It is a very important part of Interstate 75. The bridge helps travelers move between the village of Mackinaw City and the city of St. Ignace.

It is an iconic symbol for the entire state of Michigan.

Building a bridge like this is a complex way it works. A suspension bridge uses large towers to hold up the road. The main span of this bridge is 3,800 feet long. This makes it the 29th longest suspension span in the whole world. It is also the longest suspension bridge between anchorages in the Western Hemisphere.

To stay steady in high winds, the design uses a stiffening truss. This is a strong frame that supports the road deck. The road also has an open-grid middle section. This allows air to flow upward through the road. This design helps the bridge stay stable even in winds up to 100 miles per hour.

People have wanted a bridge here for a very long time. In the 1880s, people began to imagine a structure like the Brooklyn Bridge. In 1888, Cornelius Vanderbilt II suggested building a bridge to help local hotels. For many years, people had to use ferries to cross the water. By 1923, the state started a ferry service for cars. Eventually, the lines for the ferries became very long. Some drivers had to wait five hours just to get on a boat!

Engineers finally began the real work in 1954. David B. Steinman was the engineer who designed the bridge.

Construction took three and a half years to finish. It cost about $100 million to complete the project. The bridge officially opened to traffic on November 1, 1957. On that same day, the old ferry service stopped running. Governor G. Mennen Williams was the first person to pay the toll. He was also the first person to ride the very last ferry trip.

Today, the bridge is still a busy path for many travelers.

You can see large freighters passing underneath it on the water.

The bridge is a toll bridge, so drivers pay a fee to cross. This money helps pay for repairs and new parts. Every Labor Day, the governor leads a special bridge walk. This is a fun way for people to see the view from the road. The bridge remains a major part of the Great Lakes Circle Tour.

The Mackinac Bridge is a massive suspension bridge in Michigan.

It spans the Straits of Mackinac, which connect Lake Michigan and Lake Huron. This structure links the Upper and Lower peninsulas of the state. People often call it the "Mighty Mac" or the "Big Mac." It is a vital part of Interstate 75. The bridge connects the city of St. Ignace to the village of Mackinaw City. It is an iconic symbol of the state of Michigan.

Building a suspension bridge requires careful engineering to handle massive weight and wind. The bridge features a main span of 3,800 feet. This makes it the 29th longest suspension span in the world. It is also the third-longest suspension span in the United States. In the Western Hemisphere, it is the longest suspension bridge between anchorages.

This means the distance from one end's support to the other is unmatched in this part of the world. The bridge is also one of the longest bridges overall.

To keep the bridge stable, engineers used specific designs to fight wind. The design was influenced by the failure of the Tacoma Narrows Bridge in 1940. That bridge failed because it was unstable in high winds. To prevent this, designer David B. Steinman included a stiffening truss. This is a deep, strong frame that supports the road deck. The roadway itself is shaped like an airfoil, which is a shape used by wings. This shape provides lift in crosswinds. Additionally, the center two lanes use an open-grid design. This allows air to flow upward through the road. This upward airflow cancels out the lift from the wind. These features keep the bridge stable in winds up to 100 miles per hour.

For many decades, people had to cross the straits using ferries. In 1881, railroads used car ferries to connect the peninsulas. By 1923, the state of Michigan started an official automobile ferry service. Eventually, the service used nine different boats. These ferries could carry as many as 9,000 vehicles every day. However, traffic grew so large that backups were common. Some drivers had to wait in line for five hours to reach the ferry.

Ideas for a bridge appeared as early as the 1880s. In 1884, a store owner even published an artist's drawing of a proposed bridge. In 1888, Cornelius Vanderbilt II suggested a bridge to help local hotels. However, formal construction took many years to begin. During the 1930s, the Mackinac Straits Bridge Authority tried to get federal funds. They were unsuccessful because of the Great Depression. Even though President Franklin D. Roosevelt endorsed the project, Congress did not provide money. Construction was also delayed by the outbreak of World War II. Finally, the state authorized $85 million in bonds in 1952 to fund the work.

Construction finally began on May 7, 1954. David B. Steinman served as the design engineer. The project was split into two major contracts. One company handled the substructure work for $25.7 million. Another company built the steel superstructure for more than $44 million. The work took three and a half years to complete. This included four summers of work, as no construction happened in the winter. The total cost was approximately $100 million.

During this time, five workers lost their lives. The bridge opened to traffic on November 1, 1957. On that same day, the ferry service stopped running.

Today, the bridge remains a busy and important landmark. It is a toll bridge to help pay for its upkeep. In 2007, the toll was raised to fund a $300 million renovation program. This program includes replacing the bridge deck.

Travelers can see large freighters passing underneath the structure on the water.

Every Labor Day, the governor leads a traditional bridge walk. The bridge is also part of the U.S. North Country National Scenic Trail. In 2010, it was named a National Historic Civil Engineering Landmark.