Mountain Loop Hwy. over Perry Creek

Snohomish County, Washington · rated Fair in the 2025 National Bridge Inventory

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

• Mountain Loop Hwy. over Perry Creek in Snohomish County, Washington, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the substructure, rated 6 (satisfactory condition) on the 0-9 scale.
• It was built in 1958, making it 67 years old at the 2025 inventory.
• It carries about 1,273 vehicles a day (traffic count year 2022).
• Its listed owner is the county highway agency.
• It is one of 232 of the 500 inventoried bridges in Snohomish County rated fair (46.4%); 20 (4.0%) are rated poor.
• Its traffic status in the 2025 inventory is posted for load (NBI item 41).
• Its class is unchanged from 2024 (fair), but component ratings moved: deck 6 to 7, superstructure 6 to 7, substructure 5 to 6.
• Its most recent inspection on record is dated July 2024, on a 24-month routine inspection cycle.
• It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
• A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

View this bridge on a map → (48.06506, -121.50779)

Component ratings

Bridge details

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

Busiest bridges in Snohomish County

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

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