Idaho State Highway 55 Smiths Ferry latest update

Late on Saturday, Jan. 22, a slide occurred just north of Smiths Ferry on Idaho State Highway 55. This slide was in a different section than the previous slide that occurred last fall and was much smaller in scale. We were able to reopen the road less than two days later.

However, the Idaho Transportation Department (ITD) understands the impacts these closures cause the communities that are dependent on SH-55 being open and operational. While this slide was smaller and allowed crews to clear the road of snow and debris quickly, we had a responsibility to bring in experts to ensure the hillside was stable before we could fully reopen the road. Our team takes these measures out of an extreme abundance of caution because your safety is always our top priority.

Idaho is a unique state; there are only a few major highways that run north/south through our state, which means we are dependent on smaller, mountain highways. We understand SH-55 is such a crucial and high-traffic thoroughfare and is vitally important to the communities of Smiths Ferry, Donnelly, Cascade, McCall and more. We know we have an obligation to be transparent with communities in that area, travelers driving on the road, and the wider public in Idaho.

Our crews worked diligently winterizing the road last year however, there were recommended steps that were not able to be completed prior to shutting down construction. There were plans to drill and insert rods (which can be anywhere from about 10 to 30 feet long) to secure the area where the most recent slide occurred. Part of that process requires grout to be applied to secure those rods, which stabilize the rock on the hillside. When the temperatures get to a certain level, it is impossible for that grout to properly set, so the decision was made to create a buttress in that area because there was a large catchment area surrounding this section of hillside. Knowing the hillside was not fully stabilized, a catchment area and buttress was constructed, ultimately doing its job by containing 99% of the falling rock.

It is important for you to know these areas where slides occurred were still in process of completion. During the next few months, ITD is going to take another look at planned designs for securing these hillsides and put them through another geotechnical review to decide if there are other ideas we can bring to the table to further reinforce these slopes.

We sincerely appreciate the public’s patience and grace throughout this project. ITD’s mission statement is “your safety, your mobility and your economic opportunity.” The statement starts with safety because that is our top priority. We hear your concerns. We take them seriously. We will do whatever we can to keep you and your family, and your communities safe as we work toward completing this project this fall. If anyone has any additional questions, please reach out to the project team at