Skip to main content

Bridges in unincorporated King County

Baring Bridge.

Baring Bridge, Skykomish, WA.

The King County Department of Local Services, Road Services Division owns and maintains 185 bridges in the unincorporated area of King County. Built over many generations, these bridges range from less than 10 years to over 100 years in age. These bridges are an integral part of a road system that supports more than one million vehicle trips every day.

Bridge load limits and permits

Learn about bridge load limits in unincorporated King County and the overlegal permit application process.

Bridge washing

Find out about bridges that will be cleaned by King County in 2024, as a part of preventative maintenance efforts.

Bridges with weight restrictions

Access the latest updates on bridges with weight restrictions and find links to complete lists of bridges with vehicle weight, height, speed and other restrictions.

Bridge safety

Committed to bridge safety

Road Services regularly inspects the bridges we are responsible for maintaining. Sometimes we have to close bridges that are at risk including the Alvord T Bridge, which we closed in June 2013. When we are able to get grant funding, like we did with the South Park Bridge, we can replace bridges at risk rather than close them permanently.

Bridge projects

Ames Lake Bridge

Ames Lake Trestle Bridge 

This project replaces the 97-year-old Ames Lake Bridge with a wider structure and straighter bridge approaches.

Ames Lake Bridge

Baring Bridge

Baring Bridge

King County will replace the existing timber bridge with a wider, steel truss bridge., which will be open to all vehicles and carry no weight restrictions.

Baring Bridge

Coal Creek Bridge

Coal Creek Bridge

The existing 64-year-old timber support structure is decaying; the new replacement bridge will carry no weight restrictions.

Coal Creek Bridge

Duvall Slough Bridge

Duvall Slough Bridge

More than 10,000 vehicles cross the Duvall Slough Bridge on NE Woodinville-Duvall Road every day. The concrete driving surface is now too damaged to rely on short-term repairs.

Duvall Slough Bridge

Fifteen Mile Creek Bridge

Fifteen Mile Creek Bridge

We are replacing the Fifteen Mile Creek Bridge because it is past its useful life. The new bridge will be designed to meet current national bridge standards.

Fifteen Mile Creek Bridge

Upper Tokul Creek Bridge

Upper Tokul Creek Bridge

We will replace the old bridge with a new bridge that is 28 feet wide, have two 10-foot-wide travel lanes and two 4-foot-wide shoulders. The new bridge will have no weight restrictions.

Upper Tokul Creek Bridge

South Park Bridge

South Park Bridge, photo by Andrew Pogue.

The South Park Bridge on 14th Avenue S/16th Avenue S spans the Duwamish waterway. The structure is a bascule, or drawbridge, with two moveable leaves forming the main span so the bridge can be opened for marine traffic below.

South Park Bridge

Historic Bridges of King County by Eduardo Calderón

Frequently asked questions

To request the schedule for bridge maintenance, please contact the Road Services Division's Engineering Services Section by email.

expand_less