SR 108 - US 101/Mason and Thurston Co Fish Barriers - Remove Fish Barriers

Project news

  • This project addresses multiple barriers to fish under State Route 108 between McCleary and Kamilche and one location on US 101 near the Mason/Thurston County line.
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Needs & benefits

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passage barriers is an important part of the state's efforts to protect and restore fish runs negatively affected by outdated culverts under state highways.

A 2013 federal court injunction required WSDOT to significantly increase the state’s efforts in removing state-owned culverts that block habitat for salmon, bull trout, and steelhead.

Replacing outdated culverts with either bridges or fish passable structures will increase the likelihood of fish migration. The improvements will slow water and build the creek to help simulate a more natural creek environment.

Two of these locations will be corrected with concrete culverts for improved fish passage. The concrete culverts both support the highway while providing ample room for the stream to meander under the roadway.


Summer 2021 – Request for Qualifications issued

Winter 2021 – Design Builder selected 

Spring 2023 – Construction begins

Fall 2024 – Project complete


Total project costs will be published once a successful low-bid contractor has been selected.


Bill Elliott
WSDOT Project Design Engineer

Doug Adamson
WSDOT Media Relations

SR 108 and US 101 Mason and Thurston counties project map