US Bridges

SR 7 over Tilton River

Poor

Lewis County, Washington · 4.1 N JCT SR 508 · Structure no. 0001528A0000000

Built
1931
94 years old
Condition
Poor
inspected March 2023
Type
Tee Beam
Concrete
Length
38 ft
1 main span
Daily traffic
2,351
2023 count
Owner
State
State Highway Agency

About this bridge

SR 7 over Tilton River is a concrete tee beam carrying SR 7 over Tilton River in Lewis County, Washington. It was built in 1931, so it is 94 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 2,351 vehicles a day, roughly 18% of them trucks, projected to reach 2,818 by 2039. The structure is 38 ft (11.6 m) long and 27 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

Open in Google Maps
CarriesSR 7
CrossesTilton River
Location4.1 N JCT SR 508
RouteState Highway 7
CountyLewis County
StateWashington
Coordinates46.605, -122.23311
Functional classRural Minor Arterial

Condition and inspection

Poor

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.

ComponentRatingMeaning
Deck3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
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 rating67 US tons
Inventory rating40 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length38 ft (11.6 m)
Longest span36 ft (11 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,351 (2023)
Projected traffic2,818 by 2039
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 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$542,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 7 over Tilton River built?

It was built in 1931, making it 94 years old in 2025.

What condition is SR 7 over Tilton 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 March 2023.

How much traffic does SR 7 over Tilton River carry?

About 2,351 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is SR 7 over Tilton River?

The structure is 38 ft (11.6 m) long with a longest span of 36 ft (11 m) and a deck 27 ft wide.

Who owns SR 7 over Tilton River?

It is owned by the State Highway Agency.