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Seven Mile Bridge: The Longest Bridge In Florida Keys

seven mile bridge

The Seven Mile Bridge stretches across the turquoise waters of the Florida Keys and stands as a marvel of engineering and a testament to human ambition. This iconic bridge connects the islands of Knight’s Key and Little Duck Key in the sunny state of Florida. Renowned as the longest bridge in the Florida Keys, it has become an emblematic symbol of the region’s rich history, natural beauty, and adventurous spirit.

So, fasten your seatbelts and join us on a journey across the legendary Seven Mile Bridge—a true masterpiece of human ingenuity and an enduring symbol of Florida Keys.

The Seven Mile Bridge History

Seven Mile Bridge History - A Vital Link

The Seven Mile Bridge is nestled amidst the breathtaking archipelago of the Florida Keys and serves as a vital link along the scenic Overseas Highway, also known as U.S. Route 1. The bridge, originally constructed as part of the Florida East Coast Railway, has since evolved into a vital transportation artery, facilitating the flow of vehicles and offering visitors and locals an unparalleled experience.

Seven Mile Bridge History - Henry Flagler

A commercial visionary named Henry Morrison Flagler arrived in Florida in the nineteenth century. He constructed a hotel in St. Augustine and founded the Florida East Coast Railway after making millions in the oil sector.  

His train had successfully traveled to Miami by 1896. This was a significant feat. Nonetheless, Flagner was adamant about extending the railway to Key West. 

Flagler took around $30 million from his own investments in 1905. They had to navigate through wetlands with crocodiles and continually scratch mosquito bites with his crew of engineers and employees. Furthermore, his team was frequently hungry, and freshwater was only sometimes available. Workers died from heatstroke or snakebites. 

Finally, in 1908, his expedition arrived at Marathon Key. To their dismay, there were around 7 miles of open water ahead of them. Flagner, astonishingly, kept going. They had two steamships, tugboats, paddle wheelers, dredges, launches, and a catamaran at their disposal. Flagler was dispatched to England in search of a type of cement that could dry underwater. 

He employed divers to protect underwater structures. This is a challenging feat! He set up camp on Pigeon Key after two miles of construction. (Tents and bunkhouses remain as sleeping accommodations to this day.) The Old Seven Mile Bridge was finished in 1912.

Seven Mile Bridge History - Old Seven

Flagler was able to witness the result of his investment in old age, with failing eyesight, and he was praised for it. It has successfully operated for 23 years. Unfortunately, his dream railroad was killed on Labor Day in 1935. It started when the barometer began to fall. Nobody expected the most powerful hurricane ever to hit the United States.

The Category 5 hurricane surged past Matecumbe Key in the Central Keys that nightfall. Railroad officials had despatched a train to remove civilians and 800 World War I veterans who had been living in tents and working on a new road near the railroad tracks. The train was too late. See the story of Bernie Russell here – a man who lost around 50 relatives to the hurricane.

The storm claimed the lives of around 400 individuals. Nonetheless, Flagler’s dream evolved rather than vanished. The rails were quickly paved for cars, and by 1982, most of the extension’s historic bridges had closed and been replaced by new bridges, today is known as Highway 1, the Keys’ lifeline.

Seven Mile Bridge History - New Seven Mile Bridge

In March of 2022, Lonely Planet reported about the opening of the new Seven Mile Bridge. From its humble beginnings in the early 1900s, the 7 Mile Bridge has undergone several transformations to meet the growing demands of modern travel. According to the Miami Herald, the century-old 2.2-mile span has recently begun to show its age, with reports of crumbling decking and corroded and broken railings by 2016. The first phase of a 30-year, $77 million effort to restore and maintain the landmark structure began the next year. 

To that purpose, modifications were made to make Old Seven more suitable for recreational usage, including structural steel and bridge joint system repairs and new decking and handrails for pedestrians and bicycles. After a four-year, $44 million makeover, Florida’s iconic Old Seven Mile Bridge is open to runners, bikers, and pedestrians for sunrises, sunsets, and some of the best photo opportunities in the state. 

Today, the bridge is a striking combination of original construction and modern upgrades, capturing the essence of both its historical significance and contemporary functionality.

8 Best Ways To Experience The Longest Bridge In The Keys

The 7 Mile Bridge reopened several months ahead of schedule in mid-January, and the crowds have already returned. These 8 best ways to experience the Seven Mile Bridge are your key to having a meaningful but fun adventure in the Florida Keys. 

Pro Tip: The 35 parking spaces near the bridge’s base are frequently filled, even on weekdays. Look for more street parking on the other side of US 1, right past the Sunset Grille and Raw Bar. Take the picturesque walkway beneath the highway to the Old Seven Mile Bridge base from there.

1. A Long, Slow Walk Across The Old 7 Mile Bridge

What it’s like to take a walk along the newly renovated Old Seven by blab dad

The “Old Seven” is now a 2.2-mile connection between Pigeon Key and Marathon. The park is a terrific place to take in the grandeur of the Keys at a leisurely pace, despite its proximity (and yet distance) from the major route to Key West. Take as many shots as you can, enjoy the tropical South Florida sun, and stop and rest whenever you like.

With the Gulf of Mexico on one side and the Atlantic Ocean on the other, standing on Old Seven is a completely immersive experience. From the lightest turquoise to the darkest navies, what appears to be a thousand different blues mix seamlessly together. It’s an encounter that will both energize and relax your senses. 

Inhale the warm salt air and soak it all in for a memory to last a lifetime. You’re truly on island time when the only other traffic is other pedestrians, cyclists, and the occasional tram.

2. Old Seven Mile Bridge Bike Rides

A bike ride across the Old Seven by Traveling with Dana & Jodie

The Old Seven Mile Bridge’s long, flat “linear park” is ideal for a bike trip with your human and pet family members. Bicyclists and four-legged buddies abound, making it a great center for non-motorized sightseeing. Separate, dedicated lanes for bikers and walkers ensure that everyone may travel securely.

3. Spot The Wildlife Under The 7 Mile Bridge

Witness the underwater ecosystem under the Seven Mile Bridge through a GoPro footage from Fintastic Films

You never know what you’ll see if you peer over the bridge’s edge into the crystal-clear waters below (polarized sunglasses are recommended). Dolphins, sting rays, and sharks have all been observed, as have endangered Florida sea turtles and many tropical species. Look for pelicans, ibis, osprey, frigate birds, seagulls, and even a crane’s long, graceful legs as they swoop smoothly overhead.

Moreover, Fred the Tree is an iconic resident of the Old Seven Mile Bridge, even though it is not part of the bridge available to pedestrian traffic. Fred, a stray Australian Pine east of Pigeon Key and visible from the Overseas Highway as you drive past, has been growing out of the old roadbed for years and is a symbol of survival to the residents of the Keys, particularly after surviving Hurricane Irma in 2017.

4. Enjoy a Picnic Near The Seven Mile Bridge

seven mile bridge picnic

Several picnic tables are within the 7 mile bridge’s base, and you can sit in the sun or shade. It’s an opportunity to eat lunch with spectacular bay views while the warm breezes blow. Just know that no toilets are nearby.

5. Tour Pigeon Key, 7 Mile Bridge

Exploring the historic Pigeon Key by Epic Salty Life

Pigeon Key is an attraction in its own right, in addition to the recreational options given by the bridge. Pigeon Key was once home to 400 employees on Flagler’s railroad, but now it offers snorkeling, bird-watching, pier fishing, and a tiny museum with relics illustrating the island’s history.

While the Seven Mile Bridge is busy, the ancient Old Seven Mile Bridge has been closed to motor traffic and conserved as a historic landmark since the 1980s. To say it’s impressive is an understatement; the structure was once dubbed “The Eighth Wonder of the World.” 

Take a guided tram tour of Pigeon Key to get a true sense of the bridge’s impact on the early economy of the Florida Keys. You can learn more about the daily tours here.

6. Private Bridge Loop By Boat

seven mile bridge boat ride

A one-hour boat ride/loop begins at the Spanish Harbor Bridge and proceeds to the Bahia Honda Bridge, and the Seven Mile Bridge is a fantastic way to see the Keys. The boat will sail up the bay and back down the ocean (or vice versa). Learn about the history of the bridges and the Flagler Railway while also visiting mangroves and beaches. 

7. Self-Guided Audio Tour Of The 7 Mile Bridge

seven mile bridge self-guided audio tour

Take a self-guided audio tour of the gorgeous Florida Keys! This 100-mile trip connects Key Largo, the first island off the coast of Florida, to Key West, the southernmost point in the continental United States. 

This self-guided driving audio tour gives you the most flexibility and value when exploring and driving the Keys. This works: You can use a unique password and an app within 30 minutes. Download the app, input your password, and then download the tour. Begin at the first stop and proceed as directed! 

For the greatest experience, stick to the given route and speed restriction. There is no time limit – the tour is available from the moment you book. It is recommended that you purchase one trip per automobile as everyone can listen at the same time.

8. Take A Road Trip: Getting To Nearby Destinations

Driving along the Seven Mile Bridge by Backroad Driver

The major Florida Keys islands are popular for travelers to Florida’s southernmost state. And there are plenty of opportunities to enjoy a Florida Keys sunset. But, as any Overseas Highway traveler knows, getting to your resort or tourist destination is half the pleasure. 

The bridge is one of many thrills from Florida City to Mile Marker 0. The Old Seven Mile Bridge offers nearly 360-degree vistas of the Atlantic Ocean and the Gulf of Mexico, as well as the history that goes with it. Here are five nearby tourist attractions from the Old Seven (aside from the Pigeon Key:

  • Sunset Grille & Raw Bar: Located in Marathon, this waterfront restaurant offers breathtaking views of the sunset over the ocean. Known for its fresh seafood, tropical cocktails, and lively atmosphere, it’s a popular spot for locals and visitors.


  • Square Grouper Bar and Grill: Situated in Cudjoe Key, this casual waterfront eatery is renowned for its seafood dishes, including the signature “Square Grouper” sandwich. With outdoor seating overlooking the marina, it provides a relaxed and scenic dining experience.


  • Bahia Honda State Park: Just a short distance from the Seven Mile Bridge lies Bahia Honda State Park, renowned for its pristine beaches, clear waters, and diverse marine life. This picturesque park offers swimming, snorkeling, kayaking, and picnicking opportunities. Hiking trails allow visitors to explore the area’s natural beauty, and the park also has campgrounds for those looking to extend their stay.


  • Curry Hammock State Park: This beautiful state park, located on Little Crawl Key, offers a tranquil escape with its sandy beaches, swaying palm trees, and clear waters. Visitors can enjoy swimming, kayaking, birdwatching, and picnicking amidst the serene natural surroundings.


  • Sombrero Beach: Situated in Marathon, Sombrero Beach is a stunning stretch of sandy shoreline with turquoise waters. It features picnic areas, volleyball courts, and a playground, making it a great place for a beach day, sunset strolls, or a family outing.

Take In The Awe-Inspiring Backdrop Of The Seven Mile Bridge

As you traverse the length of the Seven Mile Bridge, be prepared to immerse yourself in an awe-inspiring backdrop that is bound to leave you captivated. The panoramic vistas of the crystal-clear waters of the Atlantic Ocean and the Gulf of Mexico create a breathtaking tapestry of beauty and serenity.

The Seven Mile Bridge is more than just a transportation artery; it is a gateway to a world of wonder and natural splendor. It’s a scene that words can hardly capture but must be experienced firsthand.

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Seven Mile Bridge FAQs

Nestled amidst the breathtaking archipelago of the Florida Keys, the Seven Mile Bridge serves as a vital link along the scenic Overseas Highway, also known as U.S. Route 1. The bridge, originally constructed as part of the Florida East Coast Railway, has since evolved into a vital transportation artery, facilitating the flow of vehicles and offering visitors and locals an unparalleled experience.

At the time, the Florida Keys were a series of isolated islands with limited accessibility. The construction of the railroad, including the Seven Mile Bridge, was a monumental undertaking that required overcoming significant engineering challenges, such as spanning vast open water.

 The primary purpose of the Seven Mile Bridge, along with the entire Overseas Railroad, was to provide a reliable and efficient transportation route to connect the islands of the Florida Keys.

The Seven Mile Bridge is named after its length, which spans approximately seven miles (11.2 kilometers). The bridge is known for its impressive length, which makes it one of the longest-segmented bridges in the world. The name “Seven Mile Bridge” serves as a geographic descriptor and has become synonymous with the region itself.

The time it takes to cross the Seven Mile Bridge can vary depending on several factors, including traffic conditions and the speed at which you travel. On average, driving across the entire length of the bridge takes approximately 10 to 15 minutes. It’s important to note that the speed limit on the Seven Mile Bridge and other sections of the Overseas Highway is typically 45 miles per hour (72 kilometers per hour).

The Seven Mile Bridge does not have a significant depth below its structure like an underwater tunnel or trench. Instead, it is a bridge that spans across the water’s surface. The water depth beneath the bridge varies depending on the location along its length and the tides. The waters surrounding the bridge are generally shallow, as the Florida Keys are composed of coral reefs and sandbars.

No, it is impossible to turn around or make a U-turn on the Seven Mile Bridge itself as it’s a continuous stretch of roadway with no designated turnarounds or U-turn points.

If you find it necessary to turn around while on the Seven Mile Bridge, it is recommended to proceed to the end of the bridge and reach a safe location where you can safely make a legal U-turn or find an appropriate place to change direction.

Author: Janelle

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