Fish passage work is winding down along US 12/SR 8 in Grays Harbor County. All lanes are open at three locations. Two sites on US 12 near Elma remain reduced to one lane in each direction until major work is complete.
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This project replaces five outdated culverts under US 12 and State Route 8 in Grays Harbor County between Montesano and the Thurston County line for improved fish migration.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
In fall 2025, crews will work to finish fish passage construction and open all lanes of US 12 at the remaining two work sites. Travelers will continue to see reduced lanes at the sites on US 12 near Elma. Once major work is complete, daytime lane closures may still occur for landscaping and final touches.
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This project will replace five outdated culverts at the following locations: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 - Complete
- 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 - Complete
- MP 9.10 – Unnamed Tributary to Mox Chehalis Creek - Complete
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passage barriers is an important part of the state's efforts to protect and restore fish runs negatively affected by outdated culverts under state highways.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Replacing these outdated culverts with either bridges or fish passable structures will increase the likelihood of migration through the channels.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.
