Side view of a steel girder bridge spanning a shallow creek with workers on the deck installing guardrail and construction equipment near a sheet pile wall.

Steel bridge under construction with workers installing guardrail and large sheet pile retaining wall next to an excavated dirt slope and forested background.

Bridge construction in progress with a crane operating beside the steel structure and workers along the deck above a partially dry creek bed and wooded area.

Underside view of a newly constructed steel bridge showing beams and decking above a shallow creek with exposed soil banks and surrounding vegetation.

East Silver Creek Bridge No. 16 Replacement

Ferry County was awarded state bridge replacement funding to support the design and construction of East Silver Creek Bridge No. 16 at Nine Mile Creek. This project advanced a long-anticipated infrastructure improvement for Ferry County, where maintaining reliable access for the traveling public is essential. Construction began in the summer of 2025 and reached completion in November 2025, restoring a key crossing with a modern, resilient structure designed to serve the community well into the future.

A defining element of this project is the replacement of the existing timber bridge with an 80-foot single-span steel bridge. Given the bridge’s remote location, the design prioritized efficiency, constructability, and long-term performance. Coffman’s approach to minimize on-site construction complexity while reducing long-term maintenance needs, which are critical factors for a rural crossing with limited access for repairs and upkeep, was to utilize a prefabricated steel superstructure consisting of rolled steel girders, a corrugated metal deck, and a gravel riding surface.

The replacement of East Silver Creek Bridge No. 16 addressed several challenges for Ferry County tied to aging infrastructure and environmental constraints. The previous timber bridge had limited structural capacity and maintenance concerns associated with timber components and in-stream piles. The new structure improves load capacity and aligns with current design standards, providing a safer and more reliable crossing for local and regional travel. In addition, widening the stream crossing helps reduce the risk of scour and debris buildup during high-flow events. Removal of the existing timber piles also enhances the habitat within Nine Mile Creek, supporting improved environmental conditions.

Coffman served as Prime Consultant for the project, providing project management, as well as structural, surveying, and civil design services. Coffman developed a complete bid-ready Plans, Specifications, and Estimate (PS&E) package to support construction procurement. Coffman also assisted Ferry County with construction administration, helping guide the project from design through completion while maintaining alignment with project design goals.