The Overseas Highway: 42 Bridges Built on a Railroad’s Ghost
The road runs 113 miles from Key Largo to Key West, crossing 42 bridges over open ocean. For long stretches there is nothing but asphalt, water, and sky. Most of the bridges sit on top of the old foundations of Henry Flagler’s Overseas Railroad, a project people called “Flagler’s Folly” until it was finished in 1912 and they started calling it the eighth wonder of the world instead.
A Railroad Across the Sea
Flagler started building the Key West Extension of the Florida East Coast Railway in 1905. He was 75, going blind from cataracts, and convinced that Key West, the closest deepwater U.S. port to the just-announced Panama Canal, needed a rail connection to the mainland. More than 4,000 workers laid track across open water, through mosquito swarms and tropical disease, surviving major hurricanes in 1906, 1909, and 1910. The crews worked in two shifts, 12 hours on and 12 hours off, around the clock. That marathon schedule is how the town of Marathon got its name. The railroad was completed on January 22, 1912, and Flagler, nearly blind, rode the inaugural train to Key West. He died 17 months later.
The Storm That Ended the Trains
On September 2, 1935, the most intense hurricane to ever make landfall in the United States hit the Florida Keys with sustained winds over 185 miles per hour. A rescue train was dispatched to evacuate 800 World War I veterans living in tent camps along the route, but it arrived too late. More than 400 people were killed, and 40 miles of track were destroyed. The railroad never recovered. The Florida East Coast Railway sold the damaged right-of-way to the state for $640,000. Workers paved over the old rail beds and reopened the route in 1938 as the Overseas Highway. The dismantled railroad tracks were painted white and recycled as guardrails.
Driving It Today
The Overseas Highway (U.S. Route 1) crosses 42 bridges between Florida City and Key West. The most famous is the Seven Mile Bridge, connecting Marathon to Little Duck Key, rebuilt between 1978 and 1982. A 2.2-mile section of the original railroad bridge running parallel to it reopened in 2022 for pedestrians and cyclists. The drive takes about 3.5 hours without stops, but nobody does it that way. Mile markers count down from 126 near Florida City to 0 in Key West, and every local gives directions by mile marker, not street address. Tolls were eliminated in 1954. Gas stations get scarcer south of Marathon.
