I-5 over Cowlitz River
PoorLewis County, Washington · 2.0 N Cowlitz CO · Structure no. 0004367B0000000
- Built
- 1953
- 72 years old
- Condition
- Poor
- inspected September 2023
- Type
- Truss - Thru
- Steel
- Length
- 760 ft
- 2 main spans
- Daily traffic
- 21,828
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-5 over Cowlitz River is a steel truss - thru carrying I-5 over Cowlitz River in Lewis County, Washington. It was built in 1953, so it is 72 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 4 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 21,828 vehicles a day, roughly 21% of them trucks, projected to reach 29,461 by 2039. The structure is 760 ft (231.6 m) long and 33 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 | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I-5 over Cowlitz River built?
It was built in 1953, making it 72 years old in 2025.
What condition is I-5 over Cowlitz 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 September 2023.
How much traffic does I-5 over Cowlitz River carry?
About 21,828 vehicles per day (2023 count), of which roughly 21% are trucks.
How long is I-5 over Cowlitz River?
The structure is 760 ft (231.6 m) long with a longest span of 240 ft (73.2 m) and a deck 33 ft wide.
Who owns I-5 over Cowlitz River?
It is owned by the State Highway Agency.