Overview
The Pahsimeroi River Bridge on US-93 between Challis and Salmon is reaching the end of it’s service life and plans for improvement are underway.
The Idaho Transportation Department is replacing the Pahsimeroi River Bridge on the border of Custer and Lemhi counties in Idaho. The purpose of the project is to provide an improved and safe crossing of US-93 over the Pahsimeroi River
Background- Why the Bridge Needs Replaced
The existing bridge structure crossing the Pahsimeroi River, built in 1938, is now structurally deficient and requires replacement. The current bridge does not meet current design standards for highways or bridges, and the bridge is showing significant erosion at the abutment and pier spread footings. Additionally, the turning space is inadequate at the existing intersection of US-93 and Pahsimeroi River Road resulting in the need for commercial trucks heading northbound to cross into oncoming US-93 southbound traffic in order to make the turn. On this winding stretch of river road, this presents a clear safety concern.
Alternatives Considered
- Alternative 1- Replace the existing bridge in the current location
- Alternative 2 – Realign the Pahsimeroi River . This option was developed out of a hydraulic risk assessment that investigated four different alignments to address increased safety, avoid impacts to culturally sensitive areas, and reduce construction and long-term maintenance costs. It was considered to reroute the Pahsimeroi River to just south of the post office creating a single bridge on US-93 instead of the two existing crossings.
Community Input & Preferred Alternative
ITD consulted with the Shoshone-Bannock Tribe and conducted several stakeholder interviews to solicit feedback on the alternatives. Based upon the project specific feedback and concerns raised by the Shoshone-Bannock Tribes regarding the realignment of Pahsimeroi River channel, ITD will not pursue this option. Instead, now that ITD better understands the Tribe’s priorities along with constructive input from other agencies, the Department has decided to remove the realignment of the Pahsimeroi River channel from the list of alternatives. The Preferred Alternative is to replace the US-93 bridge in its current location over the Pahsimeroi River.
Timeline
This project is currently funded for construction in 2027. In the time until then, design will be finalized, the project put out to bid and a contractor secured. Dates are subject to change based on budget needs or unforeseen delays.