SR 107 - Chehalis River Bridge - Structure Rehabilitation

Project news

  • The first of three closures for the SR 107 Chehalis River Bridge rehabilitation project is scheduled for Friday, Sept. 25 and last all weekend. Travelers will detour using US 101 through Cosmopolis - a roughly 10-mile detour. The roadway will be completely closed to all travelers beginning: 6 p.m. Friday, Sept. 25, to 6 a.m. Monday, Sept. 28. The move to the new bridge portion requires traffic to be completely off the roadway, away from heavy machinery. Emergency response vehicles will not be able to pass through the construction zone.
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  • This summer, crews will switch traffic onto the newly-constructed half of the bridge, while they rebuild the other half, demolish the timber structure and complete a bridge deck pour.
  • Grays Harbor County Roads Department closed Blue Slough Road through fall of 2020, a popular cut-through between SR 107 and US 101. Please plan accordingly.

Why is WSDOT rehabilitating the SR 107 Chehalis River Bridge?
The 1958 SR 107 Chehalis River Bridge located south of Montesano in Grays Harbor county is in need of repairs. This project replaces the timber on the south approach to the bridge, installs modern safety rails, and paints the entire steel structure on the bridge to protect against corrosion.

The End Result
A rehabilitated SR 107 Chehalis River Bridge will reduce maintenance costs and bring the south end of the bridge approach up to current standards. New paint will help preserve and protect the bridge against corrosion.

Needs & benefits

  • Reduce maintenance frequency and costs by replacing the deteriorated timber approach trestle with a concrete structure.
  • Reduces severity of collisions by installing modern traffic barriers and guardrail.
  • Preserves the steel trestle by painting.


  • Fall 2016: Finalize structure rehabilitation plan
  • September 13, 2016 Open House: Display Boards (pdf 1 MB) Invitation (pdf 238 kb)
  • Spring 2019: Advertise construction contract for competitive bidding
  • Feb. 1, 2019: Contract awarded to Rognlin's, Inc.
  • April 29: Temporary speed limit reduction signs installed
  • Summer 2019: Construction begins
  • Spring 2021: Project complete


Financial Data for PIN 310702B, 310705B
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $0
CWA $25,164
Total $25,164


Project Engineering Office
Karen Boone

Media Relations
Tina Werner

SR 107 Chehalis River Bridge small map

SR 107 Chehalis River Bridge trestle

SR 107 Chehalis River Bridge Trestle

Timber approach to the SR 107 Chehalis River Bridge

Timber approach to the SR 107 Chehalis River Bridge.

Sept 13 Open House

Montesano Open House - Sept 2016