The first time I drove the Overseas Highway, I pulled over at the first bridge long enough to get out and stand on the rail. Not because I needed to stop. Because I couldn’t keep driving while that was happening around me.
The water was four colors at once — the dark navy of the channel, the greenish blue of the shallows, the pale aquamarine near the sandbars, and a white-capped jade further out where a powerboat was crossing fast. The sky matched it. And the road — the road just kept going, arrow-straight into the water, connecting an island I’d just left to an island I hadn’t reached yet, on a highway that does this 42 times.
You don’t fully understand the Florida Keys from a map. You have to drive it.
What Is the Overseas Highway, Exactly?
The Overseas Highway is U.S. Route 1 from Florida City on the mainland to Key West at Mile Marker 0 — 113 miles of connected islands, bridges, and shallow water that makes up the Florida Keys archipelago. The road follows Henry Flagler’s original Florida East Coast Railway right-of-way, which ran from 1912 until the Labor Day Hurricane of 1935 ended it. The bridges — including the famous Seven Mile Bridge — were built on the same footings where the railroad ran.
There are 42 bridges. The longest is Seven Mile Bridge, though technically it’s 6.79 miles. You drive over open ocean for most of it, and there’s a stretch near the middle where you can see nothing but water in every direction and the horizon is a perfect, unbroken circle. It’s one of the more disorienting and beautiful driving experiences in the country.
The Keys are divided loosely into Upper, Middle, and Lower — and the character changes noticeably as you go south. The Upper Keys feel like a beach town with a fishing habit. The Middle Keys quiet down considerably. The Lower Keys and Key West are their own world.
How Long Does the Drive Take — and Should You Stop?
The pure drive, without stops, takes under three hours. Nobody does it that way, and you shouldn’t either.
The Overseas Highway is one of those roads that rewards patience. There are no freeways, no bypasses, no alternate routes. The speed limit drops through every town. At Mile Marker 82, you’ll slow through Key Largo — the first and largest island, named for Humphrey Bogart’s 1948 film but far less dramatic in reality. It’s a town of dive shops, sport fishing charters, waterfront bars, and that laid-back Keys energy that starts here and intensifies all the way to Key West.
Key Largo is where most visitors get on a boat for the first time. The John Pennekamp Coral Reef State Park — just off US-1 — is the first underwater state park in the United States, protecting about 70 nautical square miles of reef that runs parallel to the Keys. You can snorkel it, dive it, or ride a glass-bottom boat over it. The coral formations closer to shore aren’t what they were 30 years ago, but the deeper reefs still hold spectacular life. Worth a morning.
From Key Largo, US-1 winds through Islamorada — “the sportfishing capital of the world,” or so the signs say, and honestly the claim has some merit — through Marathon, through the lower island chain, and eventually onto the Seven Mile Bridge.
Practical timing: I’d structure this as a two-day drive minimum if you’re heading to Key West. Overnight in Islamorada or Marathon, not just because you’re tired but because sunrise over the Gulf side of the Middle Keys is worth staying for.
Where Are the Best Stops Along the Way?
Islamorada (Mile Markers 73–90): This cluster of small islands is where serious fishing culture lives. Robbie’s Marina at Mile Marker 77.5 is a mandatory stop — you can feed tarpon by hand from the docks. These are huge, silver, prehistoric-looking fish that roll to the surface and take the baitfish out of your hand with a sound like a dropped manhole cover. It is alarming and wonderful. There are pelicans everywhere trying to steal the bait. The whole scene is chaotic and completely free.
Long Key State Park: At Mile Marker 67.5, Long Key is one of the smaller state parks in the system and one of the best. The campground is right on the water. The snorkeling on the Atlantic side is excellent. The crowds are a fraction of what you get at Pennekamp.
Marathon and the Seven Mile Bridge: The Seven Mile Bridge is the visual centerpiece of the drive. You leave Marathon on the ocean side and you drive out over open water for the better part of seven miles. Parallel to the new bridge, you can see the old bridge — Flagler’s original railroad trestle, now a walking and biking path that extends about two miles before ending in the water. At the midpoint of the new bridge, pull into the small overlook area if there’s space. The views in both directions are the best you’ll get from a car.
Bahia Honda State Park (Mile Marker 37): Consistently ranked as one of the best beaches in Florida, and the ranking is earned. The beach on the Gulf side has that soft, pale sand and warm, clear water that defines the Keys experience. The park is small, the campground fills months in advance, but day use is worth the stop. The old Bahia Honda rail bridge sits just offshore — rusting, intact, and photogenic.
What Is Key West Actually Like at Mile Marker 0?
Key West is the most singular city in Florida, which is saying something in a state full of singular places.
The southernmost point in the continental United States — marked by a concrete buoy at the corner of South and Whitehead Streets that has a two-hour line for photos — is both a tourist cliché and a genuinely satisfying thing to stand next to. You are 90 miles from Cuba and 1,300 miles from Maine. The country ends here. The sign is accurate.
The city itself is small, walkable, and entirely itself. Old Town Key West — the historic Victorian neighborhood north of Duval Street — has the best streetscape in Florida. Conch houses with deep porches and gingerbread trim, tropical gardens spilling over wooden fences, roosters wandering free (they are a protected species in Key West, genuinely), and the persistent smell of salt air and whatever someone is cooking.
Duval Street runs the width of the island from the Gulf to the Atlantic and is the commercial heart — bars, T-shirt shops, restaurants, more bars. It gets noisy. It is not subtle. The bars close at 4am. But the side streets off Duval are quiet and beautiful, full of the architecture and pace that gave Key West its identity before anyone thought to monetize it.
Mallory Square at sunset is the thing to do once and understand why people do it. The crowd gathers — jugglers, musicians, street performers, tourists with rum drinks — and watches the sun go down over the Gulf of Mexico. It is performatively beautiful. The light at that moment, over that water, in that latitude, is not something you can fake.
What Should You Know Before You Drive It?
Fuel: Gas on the Keys is noticeably more expensive than on the mainland. Fill up in Florida City or Homestead before you cross. If you’re driving south and running below half a tank, fill up in Islamorada. Marathon has options. After Marathon, the price only goes up.
Traffic: US-1 is one lane each direction through most of the Keys. Holiday weekends — Memorial Day, Fourth of July, Labor Day — can turn the Overseas Highway into a slow crawl for hours. The Keys have no alternate route. Budget extra time or avoid those peak days entirely.
Hotels: Key West hotels book out months in advance for peak season (December through April). Islamorada and Marathon are more forgiving and often noticeably cheaper — and they’re genuinely lovely places to stay rather than just stepping stones.
Time of year: Winter is crowded and expensive. Summer is hot, humid, and prone to afternoon thunderstorms, but the rates drop significantly and the Keys still work. The shoulder seasons — late April/May and October/November — are the sweet spot. Fewer crowds, lower prices, water still warm.
I’ve driven this highway four times now. It doesn’t get old. Every time I cross that first bridge and see the water open up, I pull over for a minute. It still earns it.
Use our AI Trip Planner to build your Keys road trip — including overnight stop recommendations and timing for the Seven Mile Bridge.
Related reading: Our 2019 Florida coast-to-coast road trip | The RV drive through the Everglades and down to Key West | Key West · Key Largo · Everglades · Miami