Expect reduced lanes at five locations on US 12/SR 8 in Grays Harbor County. Travelers will see occasional rolling slowdowns as crews move traffic back to its original configuration.
Project overview
This project replaces five outdated culverts under US 12 and State Route 8 in Grays Harbor County between Montesano and the Thurston County line for improved fish migration.
What to expect
Throughout spring and summer 2025, crews will work to finish fish passage construction and open all lanes of US 12/SR 8. Travelers will see occasional rolling slowdowns. The rolling slowdowns allow crews to quickly deliver materials to the work zone and complete paving and striping. Please do not pass workers or vehicles slowing traffic. The rolling slowdowns also minimize disruptions to travelers by keeping lanes open.
Once all lanes are reopened, travelers will still see daytime lane closures until major work is complete in the fall.
This project addresses multiple barriers to fish that travel under US 12 and State Route 8 in Grays Harbor County between Montesano and the Thurston County line.
This project will replace five outdated culverts at the following locations:
US 12
- MP 12.36 – Camp Creek
- MP 17.56 – Unnamed Tributary to Wenzel Slough
- MP 19.17 – Unnamed Tributary to Vance Creek
SR 8
- MP 3.16 – Unnamed Tributary to Wildcat Creek
- MP 9.10 – Unnamed Tributary to Mox Chehalis Creek.
The Camp Creek, Wenzel Slough, Vance Creek and Wildcat Creek locations will be corrected with full span bridges. A new box culvert will be used at the Mox Chehalis Creek site. Once finished, fish will be able to navigate the channels much more easily.
Due to the extensive work required, this project will occur over a two-year period. Allowed work time in the streams ("fish windows") will be done quickly as to not disrupt the fish and their migration patterns.
Correcting fish passage barriers is an important part of the state's efforts to protect and restore fish runs negatively affected by outdated culverts under state highways.
In 2013, a federal court injunction required the state to significantly increase the state’s efforts in removing state-owned culverts that block habitat for salmon, bull trout and steelhead.
Replacing these outdated culverts with either bridges or fish passable structures will increase the likelihood of migration through the channels. Fish will be able to pass through creeks more easily as the water current will be slower, simulating a more natural creek environment.
