Green River Ferry: Mammoth Cave's cable crossing, on hold until the river rises

8.51 feet. That was the Green River at the Mammoth Cave gauge before dawn on September 25, 2026, according to the U.S. Geological Survey's provisional reading, and it is the number that explains why the Green River Ferry is tied up. The National Weather Service's impact table for that gauge says the ferry closes to all traffic when the river drops to 9.5 feet, and the Park Service's own alert confirms it: the ferry has temporarily suspended operation due to low water levels.

When the river cooperates, this is one of the more unusual pieces of road in Kentucky's national park. Mammoth Cave National Park is split in two by the Green River, with the cave tours and most visitor services on the south side and the backcountry trails, campgrounds and horse country on the north, and there is no bridge inside the park. The ferry, a small cable-guided boat operated by the Park Service, carries cars, hikers and cyclists across from 6 a.m. to 6 p.m. Central Time, on demand, with no timetable.

It is also a crossing that has spent a lot of the last two years out of action. A historic flood in April 2025 damaged its cables and towers and closed it for about eleven months; it reopened on March 5, 2026. The current stoppage is the opposite problem.

Daylight hours, no timetable, and no boat at the moment

Out of service for low water in a National Park Service alert active on September 25, 2026; hours when running as published by the park on March 3–4, 2026   NPS Mammoth Cave — Current Conditions · 2026-09-25

No fee on the park's list, but a firm size limit

The park does not publish a fare for the Green River Ferry, and its fees page, which lists what does cost money at Mammoth Cave (cave tours, camping and shelter rentals), makes no mention of it. There is no entrance fee to the park either. We describe the crossing as free on that basis, not on a statement from the park, and would correct it if a fee were announced.

What the park does limit is size. A vehicle or trailer on the ferry may weigh no more than 12 tons and be no more than 16 feet long, and the park asks anyone with a large vehicle or trailer to call ahead. Commercial vehicles are not allowed on park roads at all.

No charge for the ferry appears on any National Park Service page for Mammoth Cave read on September 25, 2026   NPS Mammoth Cave — Fees & Passes · 2026-09-25

A day-use area on the south bank, the backcountry on the north

The south ramp sits a short drive from the visitor center and the cave tours; the north ramp leads straight into the trail country on the other side of the river.

A short hop across the Green River, on a cable

The crossing is short and fixed: the boat runs along two navigational cables, each about 1,000 feet long, strung between four 20-foot towers and held by concrete anchors of roughly 15.5 tons set deep in the banks. It is the only link across the river inside the park; there are no bridges between the north and south sides.

Reading the Green River before you set out

• Below 9.5 feet, no crossing

  The National Weather Service's impact table for the Mammoth Cave gauge closes the ferry to all traffic at 9.5 feet and to RVs, trailers and heavy loads at 10.5 feet.

• High water closes it too

  At 20 feet RVs and trailers are turned away; at 32 feet, minor flood stage, the ferry closes to everyone.

• The long way round

  With the ferry shut, the nearest crossing is via KY 70 through Brownsville. To reach Maple Springs, the park's route continues on KY 259 and KY 728 over the Nolin River Dam.

• 12 tons and 16 feet

  Longer rigs and trailers should call the hotline first; the park says RVs and trailers may have difficulty on the ferry and on secondary roads.

• Hikers and cyclists ride too

  The current boat was fitted with seating and bike storage when it was relaunched in 2019.

• Call before you drive

  Ferry hotline (270) 758-2166, or @MCNPRoadsFerry on X.

From 1934 to the flood of April 2025

The Park Service dates the Green River Ferry to 1934, and says that of the river ferries the park once had, this is the only one still active; the names of Dennison Ferry and Houchin Ferry survive in a river access point and in road names on the north side. It still does two jobs at once: a scenic shortcut for visitors heading to the north-side trails, and a daily commute for people in Edmonson County who live on one bank and need the other.

Most of the recent investment has gone into keeping it running at the extremes. In 2019 the park relaunched a retrofitted boat that sits higher in the water, carries up to 12 tons and has longer ramps; in 2020 the vehicle ramps were extended 30 feet into the river so the boat could keep working at low water. Then in April 2025 the river rose to a crest of 59.54 feet at the crossing, the Park Service says, with a flow of just over 55,000 cubic feet per second; the April average is 15 to 22 feet. Part of a concrete anchor was ripped from the bank and moved 20 feet downhill, and the towers were left leaning. Repairs ran from October 2025 to February 2026, and while the boat was in dry dock it was sandblasted, repainted and given a new engine and generator along with its five-yearly Coast Guard inspection. For other crossings run by a public agency that close when the water is wrong, see Illinois's Kampsville ferry and the Gee's Bend ferry on the Alabama River.

One boat, retrofitted and relaunched in 2019

Green River Ferry questions, with the river level in mind