US Bridges

US 101 over Humptulips Overflow

Fair

Grays Harbor County, Washington · 21.3 N JCT SR 109 · Structure no. 0003765A0000000

Built
1950
75 years old
Condition
Fair
inspected June 2023
Type
Tee Beam
Concrete Continuous
Length
156 ft
3 main spans
Daily traffic
2,244
2023 count
Owner
State
State Highway Agency

About this bridge

US 101 over Humptulips Overflow is a concrete continuous tee beam carrying US 101 over Humptulips Overflow in Grays Harbor County, Washington. It was built in 1950, so it is 75 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 2,244 vehicles a day, roughly 15% of them trucks, projected to reach 2,536 by 2039. The structure is 156 ft (47.5 m) long and 34 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

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CarriesUS 101
CrossesHumptulips Overflow
Location21.3 N JCT SR 109
RouteU.S. Route 101
CountyGrays Harbor County
StateWashington
Coordinates47.22732, -123.96475
Functional classRural Principal Arterial - Other

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation7: Better than present minimum criteria
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 rating86 US tons
Inventory rating51 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length156 ft (47.5 m)
Longest span65 ft (19.8 m)
Deck width34 ft (10.4 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,244 (2023)
Projected traffic2,536 by 2039
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed31.7 mi (51 km)
TollOn a free road
National Highway SystemYes

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$2.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was US 101 over Humptulips Overflow built?

It was built in 1950, making it 75 years old in 2025.

What condition is US 101 over Humptulips Overflow 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 June 2023.

How much traffic does US 101 over Humptulips Overflow carry?

About 2,244 vehicles per day (2023 count), of which roughly 15% are trucks.

How long is US 101 over Humptulips Overflow?

The structure is 156 ft (47.5 m) long with a longest span of 65 ft (19.8 m) and a deck 34 ft wide.

Who owns US 101 over Humptulips Overflow?

It is owned by the State Highway Agency.