PORTLAND, Ore. -- Interstate 84 has been closed for nine days due to the Eagle Creek Fire and the Oregon Department of Transportation does not yet have a timeline on when it will open.

The U.S. Forest Service is estimating many popular trails in the Columbia River Gorge will be closed until next spring. Officials are worried about a heightened risk of falling rocks and trees in the already landslide-prone gorge.

“Some of the folks protecting Multnomah Falls have been reporting loud thunderous booms,” said Columbia River Gorge National Scenic Area Spokesperson Rachel Pawlitz. “Giant boulders have been coming off some sides of slopes there.”

The normally lush gorge has been scarred by wildfire. Vegetation is what keeps soil and rock sticking to steep cliffs.

“They are held in place by the moss, and they have been here for decades. So what happens when the moss gets burned away is the rocks get loose and are free to roll down the hill,” Pawlitz said.

Dead trees and root systems are no longer helping to hold the soil in place.

“When we get the fall rains even the soil will be unstable,” said Pawlitz.

The Oregon department of Transportation has already removed 3,000 trees threatening I-84.

“We have hundreds more to go and may find more,” said ODOT Spokesperson Don Hamilton.

Hamilton says ODOT has no timeline on when I-84 will be safe to open. Slides have closed the highway before, but he says this year could be even worse.

“It is really dangerous when you have underbrush burned away. This will be concerning us in the months ahead.”

Hamilton says ODOT has hired a company that will physically check loose areas of rock and trees to determine when I-84 can open.