Update #3: 12:45 p.m. 3/16/2021
Crews are removing debris from the rockslide and working to open a single lane for travel. At this time, the closure will be extended beyond 2:00 p.m. today. Conditions are variable and no estimate can be given if the highway will open today or tomorrow. Motorists are encouraged to consider an alternate route.
Geotechnical engineers have conducted a preliminary assessment and believe there is risk more rocks may slide. Current work is focused on creating protection for at least a single travel lane on the highway from additional rockfall.
ITD has coordinated with emergency service providers to ensure critical services remain available for the community.
UPDATE #2: 11:25 A.m. 3/16/2021
Photo Gallery of slide added
update #1: 10:40 A.m. 3/16/2021
Idaho Highway 55 will remain closed while crews address the rockslide. The current plan is to follow closure protocols established for the highway project during a blasting event, which requires a complete closure from 10 a.m. to 2 p.m.
The slide removed rock and earth from beneath a spire on the hillside. The stability of that spire is uncertain and the area is considered dangerous. Motorists planning to travel between Valley County and Boise County should consider alternate routes.
Another update will be provided this afternoon.
Original post: 9:30 a.m. 3/16/2021
Late in the night on March 15th, a rockslide hit Idaho Highway 55 near Smiths Ferry, closing the highway. This is located within the work zone for the Smiths Ferry to Rainbow Bridge highway improvement project. However, at this time, there is no indication the work there directly triggered the slide.
There are no known injuries at this time. An excavator being used for the project did get hit.
Geotechnical experts are evaluating the situation. Given early observations at first light, the situation remains dangerous and the highway will remain closed.
“The rock and earth in this area is historically unstable,” said project manager Alex Deduck. “We saw a significant slide in 2019 just south of here. Last night’s slide is another example why our project is so important.”
The Smiths Ferry to Rainbow Bridge project will remove thousands of tons of rock and earth from the adjacent hillside to widen the highway, create rock catchment ditches, and reduce the severity of curves. Information about the project, as well as resources to sign up for email and text alerts, can be found at itdprojects.org/id55smithsferry/.
More information will be posted on this blog post as the situation develops.
Source: Idaho DMV