The Green River Ferry in Mammoth Cave National Park will now tentatively remain closed to vehicular traffic from July 15 through Nov. 15.

Mammoth Cave National Park is postponing the closure of the Green River Ferry until July 15 or later because of construction delays.

Two years ago, the removal of Lock and Dam 6 lowered the Green River about 18 inches and subsequently caused more frequent ferry closures. The park hired a contractor to extend the vehicular access ramps by 30 feet. But the contractor will be unable to begin work before mid-July, a month behind the original schedule.

“We’re not going to close down operations unless we know they’re going to be on site, ready to start their work,” park spokeswoman Molly Schroer said.

That’s partially because most of the 250 daily passengers crossing the Green River Ferry are local residents who are commuting.

To cross the park during construction, visitors coming from the park visitor center will need to travel through Brownsville and over the Nolin River Dam. From the north, visitors should use Exit 65 from Interstate 65 toward Munfordville.

The park began planning this project shortly after removing the dam, but “there’s a lot of things to put in place and get coordinated before we put the shovels in the ground,” Schroer said.

Part of that preparation involved moving mussels living near the ferry to a safe location. In late May, scientists and conservationists helped transport nearly 2,600 mussels to a mussel bed upstream.

This number surprised the scientists, since they just relocated about 1,100 mussels from the same spot a few years ago in anticipation of the project.

But it appeared the mussels moved back in greater numbers.

“They got a lot more than they thought they would,” Schroer said. “They thought the population number would be down.”

The scientists found 28 species – including several endangered sheepnose mussels and 18 endangered fanshells – during the five-day undertaking.

This work was critical because mussels act as a filter and help clean the biodiverse river. Mussels also provide a good indication of river health.

“The healthier the (mussel) population, the healthier the river is,” Schroer said.

As of now, the contractor has indicated the work will be able to be completed on schedule by Nov. 15.

Once the project is completed, the park will launch a retrofitted ferry boat that will sit higher on the water, carry up to 12 tons of weight, including seating and bike storage, and will have ramps that reach further up the shoreline.

– For more information and for updates, visit nps.gov/maca/green-river-ferry- improvement-projects.htm.

– Follow reporter Caroline Eggers on Twitter @eggers dailynews or visit bgdaily news.com.