Give a Keys address to anyone who lives here and you will probably get a number back before you get a street. Not “1234 Overseas Highway.” Just MM 61, bayside. That is the whole address, and everyone knows exactly where it is.

Nowhere else in the country works this way. The reason is that the road we all drive was not built as a road.

Flagler’s Folly

In 1905, Henry Flagler started running rail line off the end of the Florida peninsula toward a city 128 miles out to sea. He had already built hotels and railroads down Florida’s east coast and had the Standard Oil fortune behind him. The press called the project Flagler’s Folly, which tells you what people thought of the odds.

It took seven years. The Overseas Railroad opened in 1912 and ran trains all the way to Key West. The longest single stretch over open water was the 6.7 miles between Knights Key and Little Duck Key, a span built partly of concrete arch viaduct and carried over Pigeon Key, which served as a construction camp during the build and a permanent railway camp afterward. You have driven beside it. Everyone calls it the Old Seven Mile Bridge now.

Labor Day, 1935

On Labor Day weekend of 1935, a Category 5 hurricane came ashore in the Upper Keys. It remains one of the most intense storms ever recorded to hit the United States.

Working on the bridges at the time were several hundred World War I veterans, housed in camps in the Upper Keys as part of a federal work program. A train was sent to evacuate them and did not reach them in time. Roughly two hundred of those veterans drowned in a storm surge that ran about eighteen feet. Estimates of the total death toll across the Keys range from four hundred to seven hundred people.

The railroad did not reopen. Flagler had been dead twenty-two years by then, and the company had no appetite to rebuild a line that had never really paid for itself.

What the state bought for $640,000

In 1936 the State of Florida bought the abandoned right-of-way from the Florida East Coast Railway for $640,000. What it bought was mostly bridges — dozens of them, already standing, already spanning the hardest water in Florida.

Crews laid roadway across the railbed and over the trestles. By 1938 you could drive from the mainland to Key West without waiting on a ferry for the first time in history. Those original spans carried traffic until the 1980s, when modern bridges replaced them. Twenty-three of the old railroad bridges are still standing, and stretches of them are now part of the Overseas Heritage Trail — which is why you can walk out over the water on a bridge that used to carry trains.

The Overseas Highway is a railroad with asphalt on it. That single fact explains almost everything about driving the Keys.

So why do the numbers run the way they do?

Once the highway existed, it needed a way to describe where anything was. There are no cross streets to speak of, no grid, and for long stretches no side of the road to be on other than ocean or bay. So the state did the obvious thing and numbered the miles.

Zero sits in Key West, at the corner of Whitehead and Fleming, where US-1 begins. The numbers climb going north until the road reaches the mainland around Florida City. Drive south and you count down; drive north and you count up.

The convention stuck harder here than anywhere else because nothing replaced it. A mile marker is not a landmark in the Keys. It is the address. Businesses put it on their signs, people give it out over the phone, and the post office knows what you mean.

Why a car hauler cares

Because the shape of that history is still the shape of the job.

One road in, one road out, 113 miles, 42 bridges. Every vehicle that arrives in the Keys crosses the same water Flagler’s crews crossed, on alignments they surveyed. There is no alternate route and no way to make the trip shorter. A transport company on the mainland looks at a Key West run and sees a full day for one or two cars, when the same day on I-95 moves eight. That is the honest reason so many of them will quote the job and then ask you to meet the truck in Homestead.

We built this company around that road instead of around avoiding it. When we tell you we run from MM 0 to MM 100, we are not using a marketing phrase. We are describing a railroad that a hurricane turned into a highway, and the only way in or out of these islands for anything with wheels.

Next time you pass a green sign with a number on it, that number is ninety years old and it started as a mile of track.