Umptanum Road over Anderson Slough
Kittitas County, Washington · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Umptanum Road over Anderson Slough in Kittitas County, Washington, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1982, making it 43 years old at the 2025 inventory.
- It carries about 6,083 vehicles a day (traffic count year 2022).
- Its listed owner is a city or municipal highway agency.
- It is one of 145 of the 313 inventoried bridges in Kittitas County rated fair (46.3%); 35 (11.2%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated November 2023, on a 24-month routine inspection cycle.
- 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 → (46.98097, -120.55721)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 5 | 5 | Fair condition |
Bridge details
| Structure | Steel culvert |
| Length | about 21 ft |
| Location | 0.1 W. Anderson Rd. |
| NBI structure number | 086730000000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | November 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Washington department of transportation.
Busiest bridges in Kittitas County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-90 over Coal Creek | 1928 | 18,069 | Fair |
| I-90 over Coal Creek | 1956 | 18,069 | Poor |
| I-90 over Animal Crossing | 2010 | 18,069 | Good |
| I-90 over Animal Crossing | 2012 | 18,069 | Good |
| I-90 over Gold Creek | 2011 | 18,069 | Fair |
| I-90 over Gold Creek | 2012 | 18,069 | Good |
All bridges nearby: Kittitas County, WA bridge conditions · every bridge in Kittitas County · Washington bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.