America’s Shortest Car Ferry Sails Only 200 Feet And Somehow It Makes More Sense Than A Bridge

For decades, drivers across America have used car ferries to traverse water crossings big and small. But as infrastructure needs have grown over time, many of those ferries have been partially or fully replaced by permanent bridges, which offer swifter, simpler, and more streamlined over-water transport.

There is one ferry, though, that has stood the test of time. For the past 90-plus years, the Green River Ferry has shuttled cars, as well as bikes, hikers, and other travelers, across the Green River in Mammoth Cave National Park in Kentucky. This is despite the crossing itself being around just 200 feet, and the ferry ride itself taking as little as 30 seconds.

From what I can tell, this is the shortest car ferry crossing in all of America. The boat, a single-engine barge, transports about 135,000 vehicles and 270,000 passengers a year. Drivers have to come up to the crossing, drive onto the boat, and take a 30-second ride across the water. Even with the sheer volume of riders, Mammoth Cave National Park has no plans to replace the Green River Ferry with a bridge, and that probably won’t change for a long time.

Shuttling For Nearly 100 Years

The Green River Ferry was first established in 1934, at a time when car ferries were far more common in the rural United States. It operated for years before the National Park in which it resides was actually established in 1941. Since its inception, it’s been moving travelers, locals, hikers, cyclists, motorcyclists, and park-goers between the banks of the Green River.

The ferry operates continuously, serving travelers 364 days a year (every day except Christmas), from 6 a.m. to 10 p.m. It costs the park about $2 to ferry a car across the river, but the ferry itself is totally free for all who ride it.

The ride itself is a novel experience. All you do is drive down the ramp on Maple Springs Ranger Station Road and wait for the ferry to open its boarding gate. From there, you drive on, put your car in park (or in gear and with the handbrake engaged), turn it off, and enjoy the ride. Once it reaches the other side, the gates open, and you drive off. Simple as that.

The ferry can accommodate up to two vehicles at a time, and can take between 30 seconds and a few minutes to get you across. This video from a recent crossing is a great depiction of how it all works:

Everything about this ferry just seems like it’d be a fun time (to me, at least). You don’t have to get out of your car, and you can hear the 60-horsepower diesel engine spinning the centrally located paddlewheel. The video also briefly shows what looks to be a normal grate-style park bench mounted on the deck, parallel to the cars, so passengers without cars have a place to sit during the extremely short ride.

I wasn’t able to find any photos of the inside of the pilothouse, located opposite the engine and paddlewheel, though it looks incredibly small, like it could only fit just one person. The ferry requires just one individual to operate; the park says it works on 14 shifts per week (two a day).

Here’s another video showing just how briskly the ferry moves, just to give you an idea of how quickly the ride ends:

If you look closely, you can see that two cables are running from one side of the river to the other, on either side of the ferry, suspended by support towers further up the bank. Those cables each hold additional cables, which are attached to the ferry itself. According to the park, these navigational cables act as guides for the ferry, so it doesn’t get pushed down the river by the current or wind forces. They’re replaced every three to five years.

Here’s a photo from the National Park Service, which gives a better look at where the cables are attached:

The ferry can accommodate more than just normal passenger cars and trucks. As long as your commercial truck or RV is shorter than 16 feet and under 12 tons, it can ride the ferry, too. Vehicles with trailers are another story; the ferry has its own hotline, which you can call to see if your trailer is allowed to ride.

It Might Not Be Fast, But It Is Cheap

In 2015, the National Park Service published a study on the Green River Ferry to assess its service life and propose upgrades to keep it running for the foreseeable future. Back then, the ferry could only accommodate eight tons and suffered from rusting on the hull and the internal stiffeners. Thanks to rule changes by the Coast Guard in 2010, the ferry was now also subject to inspection every two years and a dry docking for comprehensive inspection by the Coast Guard every five years.

The NPS presented several different proposals for the future of the ferry, including performing basic repairs necessary to keep it running, repairing it and upgrading it to carry heavier loads, or replacing it altogether, with a newer, more capable boat. The NPS also briefly considered a bridge, but that idea was quickly dismissed over cost—not just to build the bridge, but also to keep it operational. From the study:

Low and high level bridges were among the alternatives considered but dismissed. A low level bridge would not meet Federal Highway Administration (FHWA) standards related to high water events. While a high level bridge would meet such standards, it would have extensive environmental impacts. The bridge and connected roads would have a large footprint (both length and height of bridge out of context with the surrounding area), require excavation that could impact the cave and karst systems, have a major visual impact, and require removal of vegetation that could impact the habitat of federally threatened or endangered species. The bridge would also cost approximately $50 million to build with additional annual maintenance costs potentially exceeding those to operate the ferry. The study concluded that a bridge would be “inconsistent with the purpose of the project.”

Obviously, the NPS decided to keep the ferry around. The project cost for fixing up the boat would have cost around $3.7 million, according to the study, while building a new boat would’ve cost $4.6 million. Instead, they went for the middle option—restoring and upgrading the boat to handle more capacity—for $3.9 million. Not cheap, but a far cry from that $50 million needed to build a bridge.

In addition to all the necessary repairs needed to keep the boat floating, the NPS also replaced outdated equipment with new stuff, both to reduce costs and to ensure the boat would pass Coast Guard inspections. As for the upgrades, pontoons were added to the hull to increase capacity from 8 tons to 12 tons.

Not Without Its Faults

I’m glad this ferry exists; it’s cool to know that there’s a river crossing out there that’s broken away from the norm and embraced a fascinating, bygone way of transportation that people can still experience. But it’s not perfect. You probably already know this if you’ve paid a visit to Mammoth Cave National Park in the summer.

That same study highlights observations on traffic made by park staff, suggesting the ferry’s slow transit times may “degrade the visitor experience.” From the study:

Ferry operators and park staff have stated congestion along Green River Ferry Road can be problematic during peak season (May-August). According to their observations, as many as 30 vehicles may line up along the road waiting to cross the Green River. At low river depths which occur during the peak season, the round trip may take seven minutes or a maximum of seven trips per hour The trip takes longer at higher river depths because the distance between where the water reaches the ramps is longer. With three vehicles per trip, the thirtieth vehicle in line would have to wait more than an hour to cross the river.

There’s also the issue of flooding. Back in April, the Mammoth Cave National Park suffered a historic flooding event that ripped out one of the navigational cable’s support towers and damaged another. The flooding was so bad that it actually moved the 15-ton concrete anchor down the riverbed. From the NPS’s news release:

Traditionally during the month of April, the water level at the Green River Ferry crossing averages between 15 feet to 22 feet with a water flow just under 5,000 cubic feet per second. During the recent flood, the river reached a crest of 59.54 feet with a waterflow of just over 55,000 cubic feet per second. This high volume of water caused a portion of one of the concrete anchors to be physically pulled from the riverbank and moved 20 feet downhill. It also caused extreme stress on the four support towers which are now leaning slightly. Until the cable system and towers are repaired, the ferry cannot operate.

This damage knocked the ferry out of operation for nearly a year, with the service coming back online on March 5. In addition to fixing the cable system, the NPS also replaced the engine and added some flashy new paint. At least now, locals won’t have to do a full 40-mile loop to get to where they need to go. Until another flood comes around and disrupts service again, anyway.

While a properly built bridge would immediately solve these issues, I wouldn’t count on it, seeing as how the NPS just recently spent nearly $4 million upgrading the existing ferry. Maybe in a few decades, when the ferry needs another rejuvenation, the concept of a bridge will be back on the table. But for now, a tiny ferry that travels 200 feet, back and forth for 16 hours a day, is what makes the most sense for Green River.

Top graphic image: National Park Service