MM 127 → 0 · Overseas Highway

Florida Keys mile markers: which Key am I on?

Enter the number on a green US-1 mile marker sign, or share your location once, to see the Key you're on and nearby fuel, food, parks and lodging. The table below lists what sits along each stretch.

Southbound, top to bottom

The Overseas Highway by mile marker

Every Key KeysCompass covers, in road order, with the stretches in between. Counts are the listings the directory shows for that Key by default.

MM 107–127
Mainland approach
From Florida City down the 18-Mile Stretch to Key Largo. Top up fuel and groceries on the mainland or in Key Largo.
MM 97–107
Upper Keys · 172 listings
Key Largo
The northern gateway to the Keys, known for reef trips, dive shops and John Pennekamp Coral Reef State Park.
Essentials here Restaurants Day kit
MM 90–97
Upper Keys · 56 listings
Tavernier
A practical Upper Keys base with groceries, medical care, marinas and easy access to Florida Bay.
Essentials here Restaurants
MM 72–90
Upper Keys · 150 listings
Islamorada
A six-island village with sportfishing, galleries, waterfront restaurants and family attractions.
Essentials here Restaurants Day kit
MM 65–72
Middle Keys · 13 listings
Layton & Long Key
A quieter stretch of bridges, shoreline parks, paddling water and small-scale lodging.
Essentials here Restaurants
MM 60–65
Middle Keys · 31 listings
Duck Key
A compact resort island near family activities and the east end of Marathon.
Essentials here Restaurants
MM 47–60
Middle Keys · 159 listings
Marathon
The service hub of the Middle Keys, with an airport, hospital, marinas, boat ramps and plenty of dining.
Essentials here Restaurants Day kit Day kit Day kit Key Colony Beach (MM 53)
MM 38–47
Seven Mile Bridge stretch
Long bridges between Marathon and the Lower Keys, with no services on the bridge itself. Fuel up and take breaks on either end.
MM 36–38
Lower Keys · 15 listings
Bahia Honda
A small island dominated by one of Florida’s best-known state parks, beaches and campgrounds.
Essentials here Restaurants Day kit
MM 33–36
Between Bahia Honda and Big Pine Key
Bridges and small keys with few listed services. KeysCompass files nearby places under Bahia Honda or Big Pine Key.
MM 29–33
Lower Keys · 53 listings
Big Pine Key
The center of Key deer country, with everyday services, nature access and nearby Looe Key reef trips.
Essentials here Restaurants
MM 26–28
Lower Keys · 20 listings
Torch & Ramrod Keys
Low-key residential islands with marinas, waterfront food and quick access to backcountry water.
Essentials here Restaurants Day kit
MM 24–25
Lower Keys · 17 listings
Summerland Key
A laid-back island stop with a small airfield, marina services and local food.
Essentials here Restaurants
MM 17–23
Lower Keys · 36 listings
Cudjoe & Sugarloaf Keys
Wide-open Lower Keys scenery, boat access, RV stays and a slower pace before Key West.
Essentials here Restaurants
MM 11–17
Between Cudjoe & Sugarloaf Keys and Big Coppitt & Geiger Keys
Bridges and small keys with few listed services. KeysCompass files nearby places under Cudjoe & Sugarloaf Keys or Big Coppitt & Geiger Keys.
MM 9–11
Lower Keys · 21 listings
Big Coppitt & Geiger Keys
The last residential island communities before Stock Island and Key West.
Essentials here Restaurants
MM 5–9
Between Big Coppitt & Geiger Keys and Stock Island
Bridges and small keys with few listed services. KeysCompass files nearby places under Big Coppitt & Geiger Keys or Stock Island.
MM 4–5
Key West · 56 listings
Stock Island
A working-waterfront community with marinas, seafood, artist spaces and Key West’s eastern services.
Essentials here Restaurants Day kit
MM 0–4
Key West · 345 listings
Key West
The southernmost city: historic streets, major attractions, transit connections and the departure point for Dry Tortugas.
Essentials here Restaurants Day kit Day kit Day kit Day kit Day kit
Offshore
Dry Tortugas
About 70 miles west of Key West with no road. Ferry and seaplane departures belong with your Key West day. See the Dry Tortugas day-trip planner.

South to north

Places along the mile markers

Green mile markers on US-1, the Overseas Highway, count down to MM 0 in Key West and continue north to about MM 127 near Florida City. Treat them as approximate road posts, not exact addresses. This table lists what official sources place along each stretch.

Sourced mile-marker stretches from MM 0, south to north.
Mile marker	Area	Along this stretch
MM 0–4	AreaKey West	Along this stretch Where the Overseas Highway's mile markers end at MM 0. Key West is also where boats and seaplanes leave for Dry Tortugas. Fort Zachary Taylor Historic State Park
MM 5	AreaStock Island	Along this stretch The Stock Island public boat ramp sits at about MM 5, just east of Key West. Stock Island Public Boat Ramp
MM 20.8	AreaCudjoe Key	Along this stretch Cudjoe Gardens Marina, listed in FWC's Florida Keys boat-ramp guide. Cudjoe Gardens Marina
MM 30–31	AreaBig Pine Key	Along this stretch Pine Channel Nature Park (MM 30) and the Lower Keys Chamber (MM 31). Big Pine is the center of the National Key Deer Refuge. Pine Channel Nature Park National Key Deer Refuge Nature Center
MM 37	AreaBahia Honda Key	Along this stretch Bahia Honda State Park, with natural sand beaches. Bahia Honda State Park
MM 40	AreaLittle Duck Key	Along this stretch Veterans Memorial Park and beach at the south end of the Seven Mile Bridge. Little Duck Key Veterans' Memorial Beach
MM 40–47	AreaSeven Mile Bridge	Along this stretch The 6.79-mile span between Little Duck Key and Knights Key. The Old Seven Mile Bridge trailhead is at Knights Key, MM 47. Old Seven Mile Bridge (Knights Key Trailhead)
MM 47.5–54	AreaMarathon & Key Colony Beach	Along this stretch The Turtle Hospital (MM 48.5), Sombrero Beach (MM 50), the airport (MM 52), the Marathon Chamber (MM 53.5) and Key Colony Beach's recreation area (MM 54). The Turtle Hospital Sombrero Beach Florida Keys Marathon International Airport Greater Marathon Chamber of Commerce & Visitor’s Center Key Colony Beach Golf, Parks & Recreation
MM 58–59	AreaGrassy Key	Along this stretch Sunset Bay Park (MM 58) and the Dolphin Research Center (MM 59). Sunset Bay Park on Grassy Key Dolphin Research Center
MM 63–67.5	AreaLong Key	Along this stretch The Historic Long Key Bridge on the Overseas Heritage Trail (MM 63) and Long Key State Park (MM 67.5). Historic Long Key Bridge Long Key State Park
MM 79	AreaIslamorada (offshore)	Along this stretch Lignumvitae Key Botanical State Park lies offshore, reached only by boat. Lignumvitae Key Botanical State Park
MM 80.5–82.1	AreaIslamorada	Along this stretch Village parks along the highway: Key Tree Cactus Preserve (80.5), Library Beach Park (81.5) and Southwinds Park (82.1). Library Beach Park
MM 84.5–85	AreaWindley Key (Islamorada)	Along this stretch Theater of the Sea (MM 84.5) and Windley Key Fossil Reef Geological State Park (MM 85). Theater of the Sea Windley Key Fossil Reef Geological State Park
MM 87–90.8	AreaPlantation Key (Islamorada)	Along this stretch Founders Park (MM 87) and Plantation Tropical Preserve (MM 90.8). Founders Park Plantation Tropical Preserve
MM 92–92.5	AreaTavernier	Along this stretch The Tavernier historic area (MM 92) and Harry Harris County Park (MM 92.5). Harry Harris County Beach and Park
MM 102.5–106	AreaKey Largo	Along this stretch John Pennekamp Coral Reef State Park (MM 102.5), the Marvin D. Adams Waterway cut (MM 103.5) and the Key Largo Chamber / Florida Keys Visitor Center (MM 106). John Pennekamp Coral Reef State Park
MM 108–127	AreaNorth Key Largo to the mainland	Along this stretch Visit Florida Keys puts Key Largo's top end at MM 108. From there the markers keep climbing toward Florida City, about MM 127. The Monroe/Miami-Dade county line is at MM 113.

Mile markers are roadside posts, so a listing's MM is approximate.

Island boundaries are KeysCompass groupings (Key Largo MM 97–107, Tavernier MM 90–97, Islamorada MM 72–90); Visit Florida Keys counts Key Largo from MM 108.

Reading the road

Plan the Keys in mile markers, not street names.

Most of the Keys is one road. Restaurants, marinas, campgrounds and ramps give their location as a mile marker plus bayside or oceanside, and that is how you find the turn. Write the mile marker next to each stop in your trip planner and the day reads like a countdown.

Pick a base by stretch: the Upper Keys (Key Largo to Islamorada) for reef and fishing mornings, Marathon as the Middle Keys service hub, Big Pine and the Lower Keys for quiet nature days, and Key West as a walking city at MM 0. Then fill each day with places on that stretch so you are not crossing long bridges twice.

Practical questions

Mile marker basics

How do Florida Keys mile markers work?

Small green mile marker signs line US-1, the Overseas Highway. MM 0 is in Key West and the numbers rise heading north, reaching the mid-120s near Florida City on the mainland. Driving south toward Key West you count down; driving north you count up.

What do “bayside” and “oceanside” mean in a Keys address?

Many Keys businesses give their location as a mile marker plus a side of the highway. Bayside is the Florida Bay and Gulf side of US-1; oceanside is the Atlantic side. Pair the number with the side and you know which turn to make.

How far apart are two mile markers?

Mile markers count road miles, so the gap between two numbers is roughly the driving distance between them. MM 100 to MM 0 is about 100 road miles. Traffic, bridges and two-lane stretches decide the time, so we do not quote drive times.

Does this page track my location?

No. “Use my location” asks your browser once, compares the coordinates with directory listings on your own device, and shows the closest ones. The location is not stored or sent to KeysCompass.

Why does a mile marker show the stretch between two Keys?

Some mile markers fall on long bridges or small keys with few services, such as the Seven Mile Bridge stretch between Marathon and the Lower Keys. KeysCompass files places under the Key on either side, so the finder points you to the nearer island page.