US 12 - Unnamed Tributary to Wynoochee River - Remove Fish Barrier - Complete Nov. 2018

Project news

  • US 12 has been restored to four lane near Montesano after completion of a fish barrier correction project. Minor work remains that may require daytime single lane closures as needed through November 2018. 
  • View our construction progress.

Why is WSDOT replacing the culvert under US 12 near Montesano
The existing culvert that sends this stream under both directions of US 12 west of Montesano is a barrier to fish passage and identified needing correction. The small culvert will be replaced with a larger box culvert to improve stream flows for migratory fish. 

This work is part of WSDOT's Fish Passage Barrier Removal Program, which identifies and removes barriers to fish passage caused by culverts under state highways. Improving fish passage at this location provides adult and juvenile fish the opportunity to navigate valley-bottom agricultural lands and up into the forested headwaters where there is a greater potential for spawning habitat. WSDOT works in parternship with the Washington State Department of Fish and Wildlife to identify fish species on our state-owned culvert sites. Coho salmon and cutthroat trout are expected to utilize this upstream habitat. 

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 fish. 

The End Result
The existing culvert has been replaced with a 220-foot-long concrete box structure that will open up approximately two miles of potential fish habitat. 

Needs & benefits

  • This project will improve fish passage and open potential fish habitat for approximately two miles.
  • The work will help WSDOT comply with the U.S. District Court ruling regarding fish passage.


  • Winter 2017: Project advertised for competitive bidding.
  • Spring 2018: Contract was awarded to Rognlin's Inc.
  • Mid-Summer 2018: Estimated construction start.
  • Oct. 19, 2018: All lanes open to traffic
  • Nov. 2018: Work substantially complete. 


  • Pre-Existing Funds (PEF): $2,651,666.50
  • Total: $2,651,666.50


Tina Werner
WSDOT Communications

John Romero
WSDOT Project Engineer

US 12 - Unnamed Tributary to Wynoochee River - Remove Fish Barrier - Project vicinity map

View new traffic configuration through fall.

Existing US 12 culvert

Existing culvert has been identified as a barrier to fish passage.