Tropical Storm Helene closed the most famous road in Western North Carolina

The Blue Ridge Parkway remains closed throughout North Carolina after Tropical Storm Helene tore through the mountains last week, and the National Park Service says it doesn’t know when the road will reopen.

In North Carolina, the two-lane highway meanders 252 miles from the Virginia line to the entrance of Great Smoky Mountains National Park. All 252 miles are closed, as crews clear fallen trees and debris and assess damage to the roadway.

The park service has brought in outside help. As of late Tuesday, it said, about 100 park service employees from 22 states and the District of Columbia were in North Carolina to help Blue Ridge Parkway staff with recovery.

The parkway is both a local route for mountain residents and a huge draw for visitors who take in the mountain air and views from numerous overlooks and hiking trails along its route. The park service estimates that nearly 16.8 million people visited the parkway in North Carolina and Virginia last year, spending nearly $1.4 billion in nearby communities .

The parkway remains open in Virginia up to Shenandoah National Park . But at least parts of the road in North Carolina are likely to remain closed through fall foliage season, when traffic is often bumper to bumper.

The National Park Service has reopened U.S. 441, also known as Newfound Gap Road, which runs through Great Smoky Mountains National Park between Cherokee and Gatlinburg. As on the parkway, commercial vehicles are prohibited on U.S. 441 through the park.