Ferndale Rd over Slough

Whatcom County, Washington · rated Good in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

• Ferndale Rd over Slough in Whatcom County, Washington, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
• It was built in 1979, making it 46 years old at the 2025 inventory.
• It carries about 1,643 vehicles a day (traffic count year 2023).
• Its listed owner is the county highway agency.
• It is one of 157 of the 355 inventoried bridges in Whatcom County rated good (44.2%); 20 (5.6%) are rated poor.
• A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.

View this bridge on a map → (48.79572, -122.59519)

Component ratings

Bridge details

Source: FHWA National Bridge Inventory, 2025 data as reported by the Washington department of transportation.

Busiest bridges in Whatcom County

All bridges nearby: Whatcom County, WA bridge conditions · every bridge in Whatcom County · Washington bridges.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.