I-90 over Kachess River
PoorKittitas County, Washington · 14.8 E JCT SR 906 · Structure no. 0005702A0000000
- Built
- 1958
- 67 years old, rebuilt 1976
- Condition
- Poor
- inspected February 2024
- Type
- Slab
- Concrete Continuous
- Length
- 150 ft
- 3 main spans
- Daily traffic
- 17,108
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-90 over Kachess River is a concrete continuous slab carrying I-90 over Kachess River in Kittitas County, Washington. It was built in 1958 and reconstructed in 1976, so it is 67 years old, older than the Washington average of 49.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 17,108 vehicles a day, roughly 21% of them trucks, projected to reach 21,135 by 2039. The structure is 150 ft (45.7 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 3 Serious | Loss of section, deterioration, spalling or scour have seriously affected primary structural components. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I-90 over Kachess River built?
It was built in 1958, making it 67 years old in 2025. It was reconstructed in 1976.
What condition is I-90 over Kachess River in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in February 2024.
How much traffic does I-90 over Kachess River carry?
About 17,108 vehicles per day (2023 count), of which roughly 21% are trucks.
How long is I-90 over Kachess River?
The structure is 150 ft (45.7 m) long with a longest span of 58 ft (17.7 m) and a deck 41 ft wide.
Who owns I-90 over Kachess River?
It is owned by the State Highway Agency.