Sunset Hill Road Bridge Project in Greenough

Let us know your thoughts or questions on the preliminary design plan for a future bridge over the Blackfoot River to replace the existing Sunset Hill Road Bridge near Clearwater in Greenough.

Missoula County has developed a preliminary design plan for a future bridge to replace the existing Sunset Hill Road Bridge over the Blackfoot River outside of Clearwater in Greenough. The existing single-lane truss bridge was constructed in 1907 and now has a sufficiency rating of 19 out of 100 and is load-restricted to seven tons. Staff evaluated rehabilitating the existing bridge, but due to its age and deterioration, staff determined that rehabilitating the bridge is not the best option. This bridge is used often by locals and recreators throughout the year, with the volume increasing in summer for river recreation.

Missoula County is proposing to replace the existing structure with a single-lane truss bridge. A contractor would build the bridge with the existing piers in place and lengthen the approach spans of the new bridge. They would ensure the bridge stays on the same alignment and be slightly less than two feet wider than the existing bridge. The new bridge would accommodate all legal loads and would not have any load restrictions. The deck surface can be wood or plant mix. The deck surface type has not been determined yet, and staff has received feedback in support for a wood and plant mix deck surface.

Missoula County would be able to drive maintenance equipment over the new bridge, improving winter and summer maintenance in the area.

Replacing this bridge will cost approximately $4.1 million, and the County applied for a federal Rebuilding American Infrastructure with Sustainability and Equity (RAISE) grant, as well as a Bridge Investment Program (BIP) grant in early 2024 to help fund the replacement bridge. Missoula County Public Works heard back that they did not receive the RAISE grant, but are still waiting to hear back on the BIP grant. If the County receives the BIP grant, construction would begin in 2027 and last about six months, and the bridge would need to be closed for the duration of the project. If the County does not receive the BIP grant, staff will meet with the Federal Highway Association to find out how to improve the grant applications, and apply again the next time around.

In the meantime, let us know your thoughts or questions on the preliminary layout of the future bridge over the Blackfoot River to replace the existing Sunset Hill Road Bridge.