Park officials now believe they know what caused the massive landslide, which took out a football field-sized portion of Newfound Gap Road (US 441) on the North Carolina side.
Officials said they found a subsurface spring underneath the landslide site and they aren't quite sure how long its been there. They said the spring, along with last week's massive amounts of rainfall, contributed to the landslide Wednesday morning, near mile marker 22 between Collins Creek and Webb Overlook.
"We were unaware of this subsurface spring which causes embankment failure," said Acting Deputy Superintendent Alan Sumeriski.
Approximately 90,000 cubic yards of dirt, rock and roadway crashed 45-50 feet down the side of the mountain. Officials surveying the damage said the area is still not stable as debris continues to fall.
Officials hope to have an estimate of how much it will cost to repair the road and a rough time frame of when construction could start by next week.
According to the park, about 6,000 people use US 441 to travel between North Carolina and Tennessee during the holidays.
"While it's a challenging project to think of repair solutions, it's not impossible," Park spokesperson Dana Soehn.
The park said it also has environmental concerns regarding the landslide.
About 9,000 truckloads of dirt and roadway fell just short of the Beech Flats Prong watershed below. Sumeriski said the park would be setting up soil control and erosion measures Monday to stop soil from getting into the watershed.
