Here's the location of lots of Mile Markers on the Overseas Highway in the Florida Keys

Overseas Highway Map

No doubt the Mile Markers along the Overseas Highway that stretches the length of the Florida Keys began with the Henry Flagler Railroad. He numbered each mile of the railroad all the way from Jacksonville to Key West. In the old days there were black and white mile post signs along the railroad track and they were also on the railroads printed timetables.

Mile Marker

The Florida Department of Transportation is responsible for maintaining the Mile Markers along both sides of US Highway 1 in the Florida Keys. These signs are small green and rectangular in shape with white numbers. The Southernmost Point is at MM 0 in Key West. So as you travel up and down the Overseas Highway you’ll have a point of reference as to how far from Key West a location is. Addresses in the Florida Keys are given in Mile Markers. And it helps to remember that the even MM numbers are on the Gulf or Bay side of the highway and the odd MM numbers are on the Ocean or Atlantic side of the highway. As you travel toward Key West the numbers get smaller and as you travel toward Key Largo they get larger. If you can do math, you can figure out how many miles it is between two locations by doing a little subtraction.

I thought I’d include a list of Mile Markers Numbers just for information purposes. I’ll begin with the Monroe County Line on the Eighteen Mile Stretch and end in Key West. Keep in mind that some of the Mile Markers are missing.

Osprey Nest MM 112.5 - Is the Monroe-Dade County Line. It begins the Mile Markers in the Florida Key

MM 110.8 - FKAA Water Pump Station, oceanside and Black Water Sound Boat Ramp, gulfside

MM 109.3 - Osprey Nest, oceanside

MM 108 - Osprey Nest, oceanside

MM 107.2 - Jewfish Creek drawbridge

MM 106.6 - Lake Surprise

MM 106.5 - Card Sound Road Junction. CR 905, oceanside turn to go to Ocean Reef and toll road back to the mainland, but why would you do that?

MM 106.0 - Key Largo Chamber of Commerce, Gulfside and FKEC Power substation, Oceanside

MM 105.6 - Was the location of the railroad depot and the center of the community of Old Key Largo from 1910 - 1940. The depot was in the highway median.

Railroad Station

MM 105.5 - St. Justin Catholic Church, gulfside

MM 105.4 - Winn-Dixie Shopping Center, gulfside

MM 105.0 - Cracked Conch Restaurant, oceanside

MM 104.8 - Key Largo Elementary School, oceanside

MM 104.1 - Caribbean Club, gulfside. The location of the movie Key Largo filmed here in 1948

MM 104.0 - Italian Fisherman Restaurant, gulfside

MM 103.5 - The Key Largo Rock Castle built in the 1920s. It’s at the end of Oceana Drive, oceanside

MM 103.4 - The Marvin Adams Waterway or “The Cut,” it connects the Atlantic to Florida Bay and it’s a short cut for boaters

MM 103.8 - Central Plaza Shopping Center, gulfside

MM 102.8 - John Pennekamp Coral Reef State Park entrance, oceanside

MM 102.0 - Big Tower to help phone service in the Florida Keys, gulfside

MM 101.5 - Tarpon Basin Road. Key Largo Library and Tradewinds Shopping Center, with Publix, oceanside

MM 101.2 - Hibiscus Park, oceanside. This was the community of Newport in the 1880s.

MM 99.8 - Key largo Post Office and the Zip Code is 33037, gulfside

MM 99.5 - Woldorf Plaza, oceanside

MM 98.0 - Landings of Largo, gulfside, Moose Lodge, oceanside, Shell World in the median and Rock Harbor Club, gulfside

Mile Markers 95 - 100 was the old community of Rock Harbor. It had a railroad depot station.

MM 97.0 - Westin Hotel, gulfside

MM 95.3 - Key Largo Ocean Resorts, oceanside and Key Largo Prof. Center, gulfside

MM 95.2 - Florida Keys National Marine Sanctuary building

MM 94.8 - Seaside community, oceanside. The old Thompson packing house was here in the 1900s

MM 93.8 - Wild Bird Center, gulfside

MM 92.6 - Burton Drive, Harry Harris Park, oceanside. The old community of Planter was located where the park is today

Mile Marker 91.9 is the location of the Old Tavernier Post office, Old Settlers Park and Tavernier Hotel, oceanside. This was the center of the old community of Tavernier. The railroad depot was in the median just south of the post office.

MM 91.3 - Tavernier Town Shopping Center, Mariners Hospital and Post Office the Zip Code is 33070, gulfside

MM 91.0 - Tavernier Creek Bridge, Tavernier Creek Marina and Plantation Marina, gulfside

MM 90.1 - Plantation Key Colony entrance, gulfside. A large Indian mound was once in the center of the subdivision

MM 90.0 - 4-highway ends if your coming into the Keys. Coral Shores High School, oceanside, Plantation Key Elementary School, gulfside

MM 89.5 - Pan Pedro Catholic Church, gulfside

MM 88.5 - Plantation Key Government Center, gulfside

MM 86.8 - Treasure Village, oceanside and Rainbarrel, gulfside

MM 86.0 - Weigh Station, oceanside

MM 85.5 - Snake Creek Draw Bridge, USCG Station, gulfside

MM 85.3 - Windley Key State Fossil Reef Geological Site, gulfside

Mile Marker 84.3 is the location of the community of Quarry. It was a busy place during the construction of Flaglers Railroad

MM 84.2 - Theater of the Sea and Holiday Isle Resort, oceanside

MM 84.0 - Whale Harbor Bridge

MM 82.2 - Islamorada Chamber of Commerce, it’s in the Red Caboose, gulfside

MM 82.6 - Islamorada Post Office and the Zip Code is 33036, oceanside

MM 81.5 - The Hurricane Memorial and Cheeca Lodge, oceanside. Islamorada Library, gulfside, After the 1935 Labor Day Hurricane the library was built as a Hurricane Refuge School and at the same time the Hurricane Memorial was built and dedicated.

MM 81.2 - Worldwide Sportsman, gulfside

MM 81.3 - The Green Turtle Inn, oceanside. Part of the building was destroyed by the 1935 Labor Day Hurricane.

MM 79.8 - Tea Table Relief Bridge, Papa Joe’s, gulfside and Bud and Mary’s Marina, oceanside. The north part of the bridge was taken out by Hurricane Donna in 1960.

MM 79.1 - Tea Table Channel Bridge

MM 78.0 - Indian Key Bridge. Lignum Vitae Key Botanical Site, Lignum Vitae Key Boat Ramp, gulfside. San Pedro Underwater State Park, Alligator Reef Lighthouse and Indian Key Archaeological Site, oceanside. This Mile Marker is rich with Florida Keys history.

MM 77.1 - Lignum Vitae Bridge

MM 77.0 - Robbie’s Marina, gulfside

MM 74.0 - Angelo’s Country Store and Port Antigua subdivision, gulfside

MM 73.6 - Boy Scout Sea Base, gulfside and Calusa Cove Marina, oceanside. At this Mile Marker on the gulfside was Camp 3 for the WW-I veterans, many of them were killed by the 1935 Hurricane.

MM 73.4 - Anne’s Beach, oceanside, Veteran’s Island, gulfside. This was the approach to the veteran’s bridge piers. Mangroves and buttonwoods have grown over the area.

MM 73.0 - On the gulfside in the water are eight of the concrete bridge pilings built by the WW-I veterans.

MM 72.8 - Channel #2 Bridge

MM 71.8 - Craig Key. This key was made from fill from the railroad days. A resort was on the north end. A drawbridge was at Channel #5, the bridge tender lived at the south end of Craig Key.

MM 71.4 - Channel #5 Bridge

MM 70.0 - Fiesta Key KOA

MM 68.9 - Another tower

MM 68.5 - Layton where Long Key Post Office is located and the Zip is 33001

MM 68.0 - The Dump

MM 67.5 - Long Key State Park, oceanside

Long Key Fish Camp MM 65.8 - This Mile Marker was the location of Henry Flagler’s Long Key Fishing Camp and it’s where author, Zane Grey vacationed and wrote some of his works in the early 1900s.

MM 64.0 - You’re in the middle of Long Key Bridge

MM 63.0 - Conch Key

MM 62.2 - Little Conch Key also known as Walker’s Island

MM 61.2 - Tom’s Harbor Cut Bridge

MM 61.1 - Duck Key and Hawk’s Cay Resort, oceanside

MM 60.6 - Tom’s Harbor Channel Bridge

MM 59.9 - We made it to Marathon City Limits

MM 58.9 - Grassy Key and the Dolphin Research Center, gulfside

MM 56.2 - Curry Hammock State Park, gulfside

MM 54.6 - Coco Plum, oceanside

MM 53.5 - Village of Key Colony Beach, oceanside

MM 53.1 - Vaca Cut Bridge

MM 52.0 - Marathon Airport, gulfside

MM 50.0 - Sombrero Beach and K-Mart, oceanside and the Museum of Natural History and Crane Hammock, gulfside

MM 48.7 - Fisherman’s Hospital and Library, oceanside

MM 48.3 - Marathon Post Office where the Zip code is 33050

MM 48.0 - USCG Station and entrance to Boot Key, gulfside

MM 47.5 - Knights Key

Seven Mile Bridge Sign MM 47.0 - North end of the Seven Mile Bridge, end of Marathon and entrance to Old Seven Mile Bridge to Pigeon Key. This is one of the best places to explore that the Mile Markers mark.

MM 44.8 - Pigeon Key, gulfside

MM 43.9 - Moser Channel, you’re at the top of the arch of the Seven Mile Bridge. Sombrero Lighthouse is visible out on the oceanside

MM 40.0 - South end of the Seven Mile Bridge

MM 39.9 - Veterans Memorial Park, oceanside

MM 39.5 - Missouri-Little Duck Channel Bridge

MM 39.0 - Ohio-Missouri Channel Bridge

MM 38.8- Sunshine Key Camp Ground

MM 38.7 - Ohio-Bahia Honda Channel Bridge

MM 36.8 - Bahia Honda State Park entrance, oceanside

MM 36.0 - Bahia Honda Bridge

Bahia Honda Bridge MM 34.7 - Another Tower

MM 34.5 - Girl Scout Camp, oceanside

MM 34.1- Boy Scouts Camp Sawyer, oceanside

MM 34.0 - West Summerland Key

MM 34.5 - Spanish Harbor Bridge

MM 31.0 - Lower Keys Chamber of Commerce

MM 30.2 - Traffic light on Big Pine Key . In season this one of the traffic jam Mile Markers. Wilder Road and Key Deer Blvd., gulfside, you’ll find a shopping center, the road prison and if you keep going long enough you’ll find No Name Key. The No Name Pub and the Old Wooden Bridge Fishing Lodge are out there somewhere.

No Name Key Sign MM 30.0 - Big Pine Key Post Office where the Zip is 33043

MM 29.3 - North Pine Channel Bridge

MM 28.5 - South Pine Channel Bridge

MM 28.1 - Little Torch Key

MM 28.0 - Torch Channel Bridge

MM 27.9 - Middle Torch Key and turn off for Big Torch Key, gulfside

MM 27.7 - Torch-Ramrod Channel Bridge

MM 27.0 - Ramrod Key

MM 26.0 - Arch of the Niles Channel Bridge

MM 25.0 - 24.0 - Summerland Key my favorite of all the Mile Markers

MM 24.8 - Summerland Key Post Office and our Zip is 33042

MM 24.0 - Boy Scout Sea Base

MM 23.5 - Kemp Channel Bridge

Fat Albert MM 21.5 - Blimp Road, Cudjoe Key. The dump is down this road and so it our Blimp, Fat Albert . Look up and see him in the air about 10,000 feet. This is the only blimp for the Mile Markers to mark.

MM 20.2 - Bow Channel Bridge

MM 20.0- Mangrove Mama’s gulfside and Sugarloaf KOA Campground, oceanside

MM 19.3 - Crane Blvd., Sugarloaf School, gulfside

MM 18.6 - Upper Sugarloaf Key

MM 18.8 - Park Channel Bridge

MM 17.8 - North Harris Channel Bridge

MM 17.6 - Harris Gap Channel Bridge, the shortest bridge in the Florida Keys

MM 17.5 - Lower Sugarloaf Key

MM 17.5 - Blinking light at Sugarloaf Blvd., oceanside, Sugarloaf Airport, Sugarloaf Lodge and Marina and the Bat Tower, gulfside

MM 16.3 - Harris Channel Bridge

MM 15.8 - Lower Sugarloaf Channel Bridge

MM 15.0 - Old US Army transmitter site which is now Radio Marti, gulfside

MM 14.6 - Saddlebunch #2 Bridge and Bay Point Subdivision, oceanside

MM 14.3 - Saddlebunch #3 Bridge

MM 13.1 - Saddlebunch #4 Bridge

MM 12.8 - Saddlebunch #5 Bridge

MM 11.4 - Shark Channel Bridge

MM 11.2 - Shark Key

MM 11.0 - Big Coppitt Boat Ramp, oceanside

MM 10.5 - Old Boca Chica Road to Geiger Key

Southernmost Point in Key West

MM 10.0 - Big Coppitt Key

MM 9.7 - Rockland Channel Bridge

MM 9.2 - Rockland Key

MM 8.0 - NAS Boca Chica Naval Station

MM 6.1 - Boca Chica Bridge

MM 5.2 - Key Haven

MM 5.0 - Stock Island, turn off to the Hospital, College, Jail, Golf Course and dump, gulfside

MM 4.1 - Cow Key Channel Bridge

MM 3.9 - Traffic light, turn left to go to the Airport and right to go down town

MM 3.0 - Sears Town Shopping Center

MM 2.3 - Salt Run Bridge

MM 1.7 - Palm Avenue, it’s the short cut to down town Key West

MM 1.0 - South Street

MM 0.0 - Southernmost Point to the south and Key West Post Office where the Zip is 33042 in the middle of Whitehead Street. This is probably the most famous of all the Mile Markers.

I hope you’ll be able to use these Mile Marker locations to help find your way around while in the Florida Keys.

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