US Bridges

SR 6 over Chehalis River

FairPosted for load

Lewis County, Washington · 26.3 E Pacific CO · Structure no. 0002538B0000000

Built
1939
86 years old
Condition
Fair
inspected May 2023
Type
Truss - Thru
Steel
Length
1,045 ft
1 main span
Daily traffic
11,576
2023 count
Owner
State
State Highway Agency

About this bridge

SR 6 over Chehalis River is a steel truss - thru carrying SR 6 over Chehalis River in Lewis County, Washington. It was built in 1939, so it is 86 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 11,576 vehicles a day, roughly 6% of them trucks, projected to reach 15,056 by 2039. The structure is 1,045 ft (318.5 m) long and 25 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSR 6
CrossesChehalis River
Location26.3 E Pacific CO
RouteState Highway 6
CountyLewis County
StateWashington
Coordinates46.65764, -122.98597
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41 US tons
Inventory rating27 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+42 approach)
Design loadH 15
Structure length1,045 ft (318.5 m)
Longest span240 ft (73.2 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deck15 ft (4.5 m)

Traffic and service

Average daily traffic11,576 (2023)
Projected traffic15,056 by 2039
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$16.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 6 over Chehalis River built?

It was built in 1939, making it 86 years old in 2025.

What condition is SR 6 over Chehalis River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in May 2023.

How much traffic does SR 6 over Chehalis River carry?

About 11,576 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 6 over Chehalis River?

The structure is 1,045 ft (318.5 m) long with a longest span of 240 ft (73.2 m) and a deck 25 ft wide.

Who owns SR 6 over Chehalis River?

It is owned by the State Highway Agency.