Downed trees litter the Blue Ridge Parkway near milepost 375 in North Carolina/NPS

Ongoing assessments of storm damage on the Blue Ridge Parkway have found significant, and in some cases castrophic, damage between mileposts 280 and 469, the National Park Service said Saturday.

The entire length of the parkway, stretching from Shenandoah National Park in Virginia to Great Smoky Mountains National Park in North Carolina, remained closed. The agency made no hard prediction when sections of the famed road might reopen.

"In the coming weeks, the assessment teams will utilize the data from their inspections to determine the full extent of the damage including the timeline and cost estimates for repairs. A projected reopening date of any section of the Blue Ridge Parkway in North Carolina has not yet been established," a Park Service release said. "In Virginia, damage assessments and the clearing of debris from the road are nearing completion, which will for allow a phased reopening in Virginia in the coming days to weeks."

Tropical Storm Helene brought heavy rains and strong winds to Appalachia, downing trees and sending floodwaters down rivers and streams that in turn washed out bridges and undercut roads in some places. On the Blue Ridge Parkway, erosion tore out a section of pavement in both directions at Gooch Gap at milepost 336.5, and part of the pavement near the Ferrin Bridge at milepost  401.3.

Elsewhere in the region, some park units that have been closed the past week were planning to reopen. Among them was Cumberland Island National Seashore in North Carolina, which planned to open Sunday. Congaree National Park in South Carolina had reopened, as did Overmountain Victory National Historic Trail, which touches Virginia, Tennessee, North Carolina, and South Carolina.

Still closed, according to Park Service websites, were Cowpens National Battlefield, Kings Mountain National Military Park, and Ninety Six National Historic Site, all in South Carolina, and the Carl Sandburg Home National Historic Site in North Carolina.

Southern sections of the Appalachian National Scenic Trail also were said to be tangled in downed trees, and the Park Service and Appalachian Trail Conservancy were advising against hiking them. National forests where the A.T. passes through in North Carolina, Tennessee, and southwest Virginia were closed, the agency said. Specific closure information can be found here.