Patterson Creek Bridge replacement begins Aug. 16

Section of Southeast Duthie Hill Road to close for three months

The King County Road Services Division begins construction Aug. 16 to replace the more than 60-year-old Patterson Creek Bridge. Work will completely close the narrow two-lane bridge on Southeast Duthie Hill Road near State Route 202 for up to three months.

The bridge, located between Sammamish and Fall City, was built in 1951 and its creosote-treated timber supports are decaying. When complete, the replacement bridge will increase safety and improve traffic flow for the more than 5,200 vehicles that use the road daily. The current bridge is 24 feet wide with narrow shoulders, and the new bridge will be 38 feet wide with two 11-foot-wide traffic lanes and 8-foot-wide shoulders.

Commuters are advised to use alternate routes during the closure. A posted detour will direct drivers to Old Southeast Issaquah-Fall City Road. The road and new bridge are anticipated to reopen to traffic by Nov. 16.

MidMountain Contractors Inc. is allowed to work daytime hours seven days a week. Crews will start site preparation work as early as Aug. 13. Support pilings for the new bridge are scheduled to be installed later this month. Approaches to the bridge will be built on Geofoam – rigid light-weight Styrofoam – that will better support the roadway across the weak peat soils and avoid settling.

More information about the $3.1 million project is posted on the project website.