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.

Update: Sunset Hill Road Bridge in Greenough has been closed indefinitely due to structural concerns. The bridge is closed to all traffic, including foot traffic. Drivers will need to take an alternate route.

Missoula County has developed a preliminary design plan to replace the existing Sunset Hill Road Bridge 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 currently closed due to a poor Montana Department of Transportation (MDT) sufficiency rating. The MDT inspection in September 2025 demonstrated that the bridge can no longer carry traffic safely or reliably.

The County is asking local engineering firms to take a preliminary look at the bridge to understand the cost effectiveness of replacing a damaged vertical support. This bridge is often used by locals and recreators throughout the year, with the volume increasing in summer for river recreation. The County is also working with local landowners to provide parking on the south side of Sunset bridge during this closure.

Missoula County is proposing to replace the existing structure with a single-lane truss bridge. A contractor would build the bridge with the existing vertical supports (piers) in place and lengthen the connection from the bridge to land (approach spans). They would ensure the bridge stays on the same alignment and be two feet wider than the existing bridge. The new bridge would accommodate all legal loads and would not have any load restrictions. This includes Missoula County maintenance equipment – greatly improving winter and summer maintenance in the area.

The bridge surface (deck) can be made of wood or plant-mix. Although nothing has been confirmed, staff have received positive feedback for this type of surface material.

Replacing this bridge will approximately cost $4.6 million. Missoula County unsuccessfully applied for two federal grants in 2024 to help fund the replacement bridge. The County will be applying for the Bridge Investment Program (BIP) in FY 2026.