US Bridges

SR 109 over Humptulips River

Fair

Grays Harbor County, Washington · 10.3 N JCT US 101 · Structure no. 0004874B0000000

Built
1956
69 years old
Condition
Fair
inspected May 2024
Type
Truss - Thru
Steel
Length
364 ft
1 main span
Daily traffic
6,510
2023 count
Owner
State
State Highway Agency

About this bridge

SR 109 over Humptulips River is a steel truss - thru carrying SR 109 over Humptulips River in Grays Harbor County, Washington. It was built in 1956, so it is 69 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 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 6,510 vehicles a day, roughly 6% of them trucks, projected to reach 7,024 by 2039. The structure is 364 ft (110.9 m) long and 32 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

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CarriesSR 109
CrossesHumptulips River
Location10.3 N JCT US 101
RouteState Highway 109
CountyGrays Harbor County
StateWashington
Coordinates47.05079, -124.0425
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34.9 US tons
Inventory rating20.9 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+4 approach)
Design loadHS 15
Structure length364 ft (110.9 m)
Longest span234 ft (71.3 m)
Deck width32 ft (9.8 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deck15 ft (4.6 m)

Traffic and service

Average daily traffic6,510 (2023)
Projected traffic7,024 by 2039
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed19.9 mi (32 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$6.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 109 over Humptulips River built?

It was built in 1956, making it 69 years old in 2025.

What condition is SR 109 over Humptulips 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 2024.

How much traffic does SR 109 over Humptulips River carry?

About 6,510 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 109 over Humptulips River?

The structure is 364 ft (110.9 m) long with a longest span of 234 ft (71.3 m) and a deck 32 ft wide.

Who owns SR 109 over Humptulips River?

It is owned by the State Highway Agency.