Landslide video shows mountain moving

A video taken by an Idaho Transportation Department worker shows the dramatic movement of a mountain hillside onto U.S. Highway 95 south of Bonners Ferry last Friday.

A land surveyor for the transportation department and a worker for a private traffic company were at the scene of the slide after several smaller slides had blocked part of the highway and were cleared.

They heard cracking and popping and realized that more of the mountain was ready to slide down onto the highway, which was already protected by two rows of jersey barriers, said Jake Melder, a spokeswoman for the transportation department.

They got traffic stopped about three minutes before the slide, Melder said.

Surveyor Mathew Wilson took the video.

Melder said the slab of earth was estimated at 10 feet deep with mature trees on the top. The soil appears to be a sedimentary formation.

Small rivulets of water apparently had formed underground prior to the slide, Melder said. The rivulets can be seen in the video after the slide moves down the hillside.

The seeming slowness of the slide may have been due to roots and overburden in the slide, he said.

Traffic has been reduced to one lane with flaggers directing alternating traffic as of Wednesday, Melder said.

After the Friday slide, crews cleared debris from the roadway, estimated at 800 cubic yards. Another 600 cubic yards were removed along the shoulder to make way for water drainage.

Melder in a later news release, said, “This section of hillside continues to be unstable. Crews have noted progressive shifting near U.S. 95.”

“Rain is in the forecast and there remains 18 inches of snow above the slide area. ITD is working with geology specialists to assess the situation. With public safety as a priority, additional traffic control measures may be taken,” he said.