The end of the road? What’s coming for this iconic Idaho bridge
Since 1933, Idahoans traveling on Idaho 55 over the North Fork of the Payette River have relied on the iconic Rainbow Bridge. Just north of Smiths Ferry and an hour outside McCall, the bridge is listed in the National Register of Historic Places.
But the years are catching up with it.
For years, the Idaho Transportation Department had been planning to replace the aging bridge to accommodate increased traffic, while exploring scenarios to keep the existing bridge as a pedestrian walkway and landmark, the Idaho Statesman previously reported.
But after an evaluation of the bridge’s condition, completed in 2024, the department is now proposing to remove it entirely, according to a webpage it created to solicit public feedback.
With “extensive” deterioration and “significant and widespread” corrosion in the bridge’s concrete, “keeping the bridge will require a significant effort and investment,” the department said.
The department cited safety risks, future maintenance costs and the lack of options to use the bridge as anything other than a landmark even with that maintenance. But community input about the proposed removal will influence the department’s decision, ITD said.
The department laid out three scenarios that would allow the original bridge to remain alongside a new one, with costs ranging from about $20 million to about $50 million. But none of the scenarios would allow vehicle or pedestrian traffic to use the bridge.
The department is accepting feedback about its proposals for the existing bridge until Aug. 5 and will make a decision within the next year, said John Tomlinson, a spokesperson for the department.
Over the Rainbow: Plans for new Payette bridge
Whether the Rainbow Bridge stays or not, it “cannot continue” to carry vehicle traffic, the department said. So the department is moving ahead with plans for a new bridge just west of the existing bridge.
The new bridge will have two 12-foot lanes and 14-foot shoulders across the bridge, as well as 17-foot shoulders on the curves before and after the bridge. The department will also construct retaining walls near the new bridge, ITD said, which will stabilize the canyon slopes and allow the existing bridge to remain open during construction.
The department is accepting feedback on nine proposed bridge designs until Aug. 5. Residents can follow the project’s progress at sh55rainbowbridge.com.
The department is conducting maintenance on the existing bridge this summer, ITD said, which will allow travelers to continue to use the bridge until the new one is built in 2028.
