Richardson Creek Bridge 300 Replacement


Richardson Creek Bridge 300, located at milepost 0.67 on Woods Creek Road northeast of Monroe, is currently being designed for replacement. The existing short span bridge was built in 1961 and does not support the current traffic needs of the area. The current bridge is 18 feet long and 22 feet wide, with precast concrete girders, and supported on timber piles.


The proposed replacement bridge will improve mobility for the nearly 6000 daily vehicles using this arterial road by widening the bridge deck. The new design adds sidewalks and bike lanes for active transportation. The proposed new bridge will be lengthened to remove structure supports from the flood waters of Richardson Creek. It will also help fish passage at the site.

Engineering and design for the Richardson Creek Bridge replacement is in process.

Traffic Impacts

Replacing Bridge 300 will disrupt the flow of the 6000 vehicle trips each day across this bridge. Project cost, worker safety, commute times and construction duration are important considerations. The county is evaluating several options for bridge replacement and managing vehicle traffic during the construction phase, including:

  • Option 1: Provide a full road closure that is safer for construction, but requires detouring all traffic around the project site. The proposed detour route utilizes Ingraham Road, 132nd St. SE, and Wagner Road.
  • Option 2: Build the bridge in two stages, one half at a time. The daily impact to commuters may be reduced, but the construction would last longer.

The construction of this project may begin in 2024 pending the acquisition of construction funding and permitting approvals. 


Present - 2023

  • Design
  • Survey
  • Environmental Review
  • Right-of-Way Acquisitions, if applicable

2024 (tentative)

  • Construction


Funding has been secured for the design of the replacement bridge. It includes 85% federal funding from the Surface Transportation Program (STP) and 15% from the Snohomish County Roads Fund. The total project cost is estimated at approximately $2.6 million. The county is working on securing grant funding for construction of the new bridge.

Public Meeting

Snohomish County Public Works held an open house to discuss the Richardson Creek Bridge replacement project and seek input on two construction proposals on October 9, 2019. Information about the project was available along with project experts to answer questions.