US Bridges

SR 107 over Slough

Fair

Grays Harbor County, Washington · 7.6 N JCT US 101 · Structure no. 0004381A0000000

Built
1953
72 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
307 ft
16 main spans
Daily traffic
4,428
2023 count
Owner
State
State Highway Agency

About this bridge

SR 107 over Slough is a wood or timber stringer/multi-beam or girder carrying SR 107 over Slough in Grays Harbor 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 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.

It carries about 4,428 vehicles a day, roughly 10% of them trucks, projected to reach 4,966 by 2039. The structure is 307 ft (93.6 m) long and 28 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

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CarriesSR 107
CrossesSlough
Location7.6 N JCT US 101
RouteState Highway 107
CountyGrays Harbor County
StateWashington
Coordinates46.97031, -123.60131
Functional classUrban 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 protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no 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 adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans16
Design loadHS 15
Structure length307 ft (93.6 m)
Longest span19 ft (5.8 m)
Deck width28 ft (8.4 m)
Roadway width22 ft (6.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,428 (2023)
Projected traffic4,966 by 2039
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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$4.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 107 over Slough built?

It was built in 1953, making it 72 years old in 2025.

What condition is SR 107 over Slough 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 April 2024.

How much traffic does SR 107 over Slough carry?

About 4,428 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is SR 107 over Slough?

The structure is 307 ft (93.6 m) long with a longest span of 19 ft (5.8 m) and a deck 28 ft wide.

Who owns SR 107 over Slough?

It is owned by the State Highway Agency.