US Bridges

US 12 over Mox Chehalis Creek

Fair

Grays Harbor County, Washington · 4.5 E JCT SR 8 · Structure no. 0002236B0000000

Built
1937
88 years old
Condition
Fair
inspected October 2024
Type
Tee Beam
Concrete Continuous
Length
165 ft
4 main spans
Daily traffic
5,851
2023 count
Owner
State
State Highway Agency

About this bridge

US 12 over Mox Chehalis Creek is a concrete continuous tee beam carrying US 12 over Mox Chehalis Creek in Grays Harbor County, Washington. It was built in 1937, so it is 88 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 5,851 vehicles a day, roughly 13% of them trucks, projected to reach 6,831 by 2039. The structure is 165 ft (50.3 m) long and 31 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

Open in Google Maps
CarriesUS 12
CrossesMox Chehalis Creek
Location4.5 E JCT SR 8
RouteU.S. Route 12
CountyGrays Harbor County
StateWashington
Coordinates46.95669, -123.32725
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be 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 rating24.3 US tons
Inventory rating19 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length165 ft (50.3 m)
Longest span65 ft (19.8 m)
Deck width31 ft (9.4 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,851 (2023)
Projected traffic6,831 by 2039
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed14.3 mi (23 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 12 over Mox Chehalis Creek built?

It was built in 1937, making it 88 years old in 2025.

What condition is US 12 over Mox Chehalis Creek 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 October 2024.

How much traffic does US 12 over Mox Chehalis Creek carry?

About 5,851 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is US 12 over Mox Chehalis Creek?

The structure is 165 ft (50.3 m) long with a longest span of 65 ft (19.8 m) and a deck 31 ft wide.

Who owns US 12 over Mox Chehalis Creek?

It is owned by the State Highway Agency.