Mosquito Lk Rd over Middle Fork
Whatcom County, Washington · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Mosquito Lk Rd over Middle Fork in Whatcom County, Washington, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1915 and reconstructed in 2010, making it 110 years old at the 2025 inventory.
- It carries about 117 vehicles a day (traffic count year 2024).
- Its listed owner is the county highway agency.
- It is one of 178 of the 355 inventoried bridges in Whatcom County rated fair (50.1%); 20 (5.6%) are rated poor.
- 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 → (48.78462, -122.11314)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 8 | Very good condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 7 | Good condition |
Bridge details
| Structure | Steel through truss |
| Length | about 431 ft |
| Location | 05.2 SE Mt. Baker Hwy |
| NBI structure number | 081574000000000 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Washington department of transportation.
Busiest bridges in Whatcom County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-5 over Orchard Dr/squalicum CR | 1958 | 39,925 | Fair |
| I-5 over Orchard Dr/squalicum CR | 1958 | 39,925 | Fair |
| I-5 over Meador Ave | 1957 | 38,169 | Fair |
| I-5 over Meador Ave | 1957 | 38,169 | Fair |
| I-5 over Iowa St | 1957 | 33,565 | Fair |
| I-5 over Whatcom Creek | 1957 | 33,565 | Fair |
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.