Pilchuck River Bridge 581

December 2016 update

The Pilchuck River Bridge 581 project has been delayed and the bridge is expected to be closed through January 2017. The supplier of the prefabricated bridge delivered the bridge 10 weeks late due to issues with the materials. Final asphalt paving and environmental mitigation work will take place intermittently in the spring and summer of 2017.
April  2016 through January 2017
The bridge construction zone will be closed to public access:
  • No river access
  • No pedestrian access
  • No parking
  • No turnaround


Pilchuck River Bridge 581 is located on 64th St NE in the Lochsloy community, between Granite Falls and Lake Stevens. The existing bridge, a multiple-span one-lane steel and timber structure originally built in 1960. The replacement bridge will be a single-lane, single-span structure. The new steel truss design will eliminate the need for intermediate support piers in the river and help to reduce debris accumulation under the bridge. The new bridge is being constructed immediately upstream of the existing bridge and will be completed by the fall of 2016.


The total cost of the bridge replacement project is estimated at approximately $4.5 million. A federal bridge replacement grant will fund 80% of the cost, with the remaining 20% supplied by local matching funds.

Northwest Hydraulic Consultants (NHC) was retained to prepare a Channel Migration Zone (CMZ) Study, which was completed in February 2013. Snohomish County Surface Water Management staff conducted the hydraulic modeling during 2013; the report was completed in September 2013. Information from the modeling and the required CMZ study is essential for designing the bridge. 


Construction is currently underway on the Pilchuck River Bridge 581 and is estimated to be completed by the end of January 2017. Final paving and environmental mitigation work will take place in the spring and summer of 2017.