US Bridges

SUNSET/3360 over Cottonwood Creek

Fair

Whitman County, Washington · 1.98 MI NE Pne Cty-Malden · Structure no. 083852000000000

Built
1966
59 years old
Condition
Fair
inspected December 2023
Type
Tee Beam
Prestressed Concrete
Length
36 ft
1 main span
Daily traffic
90
2021 count
Owner
County
County Highway Agency

About this bridge

SUNSET/3360 over Cottonwood Creek is a prestressed concrete tee beam carrying SUNSET/3360 over Cottonwood Creek in Whitman County, Washington. It was built in 1966, so it is 59 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 90 vehicles a day, roughly 25% of them trucks, projected to reach 90 by 2044. The structure is 36 ft (11 m) long and 30 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

Open in Google Maps
CarriesSUNSET/3360
CrossesCottonwood Creek
Location1.98 MI NE Pne Cty-Malden
RouteCounty Highway 33600
CountyWhitman County
StateWashington
Coordinates47.12163, -117.53268
Functional classRural Minor Collector

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating35.1 US tons
Inventory rating22.8 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadH 20
Structure length36 ft (11 m)
Longest span34 ft (10.4 m)
Deck width30 ft (9.1 m)
Roadway width30 ft (9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic90 (2021)
Projected traffic90 by 2044
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SUNSET/3360 over Cottonwood Creek built?

It was built in 1966, making it 59 years old in 2025.

What condition is SUNSET/3360 over Cottonwood 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 December 2023.

How much traffic does SUNSET/3360 over Cottonwood Creek carry?

About 90 vehicles per day (2021 count), of which roughly 25% are trucks.

How long is SUNSET/3360 over Cottonwood Creek?

The structure is 36 ft (11 m) long with a longest span of 34 ft (10.4 m) and a deck 30 ft wide.

Who owns SUNSET/3360 over Cottonwood Creek?

It is owned by the County Highway Agency.