LEWISTON – Following persistent rain over the last week, a rockfall blocked lanes this morning on U.S. Highway 95 at the top of White Bird Grade south of Grangeville. The highway remains reduced to one lane.
Rocks ranging from 6 inches to 6 feet wide blocked the southbound lane around 10 a.m. Crews immediately responded by alternating northbound and southbound traffic and hauling away debris.
Rocks continued to fall down the slope, prompting the Idaho Transportation Department to place concrete rail to protect drivers. A spotter will watch the hillside through the night, ready to close the highway at a moment’s notice. Flaggers will control traffic through tonight and likely tomorrow night.
“This happened during blue skies,” Operations Engineer Jared Hopkins said. “Just a reminder that sometimes it takes a bit for rain to seep into a slope and make it unstable.”
Experts will continue to monitor the site. The department is arranging for large railroad containers to be placed at the edge of the highway to block any future rockfall.
“We will let this settle overnight, but in the morning our goal is to continue removing debris,” Hopkins said. “Once larger barriers are in place, we’re hopeful to have one lane in each direction while we identify a long-term solution.”
The department is also working to secure an emergency contract to use specialized equipment to scale the slope, a process that involves knocking down loose debris proactively.
Drivers are encouraged to monitor road conditions at 511.idaho.gov.