US Bridges

Umptanum Road over Yakima River

Fair

Kittitas County, Washington · 00.37 W I-90 · Structure no. 081098000000000

Built
1971
54 years old
Condition
Fair
inspected November 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
306 ft
1 main span
Daily traffic
6,083
2022 count
Owner
County
County Highway Agency

About this bridge

Umptanum Road over Yakima River is a concrete continuous box beam or girders - multiple carrying Umptanum Road over Yakima River in Kittitas County, Washington. It was built in 1971, so it is 54 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 6,083 vehicles a day, roughly 25% of them trucks, projected to reach 7,001 by 2038. The structure is 306 ft (93.3 m) long and 32 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesUmptanum Road
CrossesYakima River
Location00.37 W I-90
RouteCounty Highway 96937
CountyKittitas County
StateWashington
Coordinates46.97771, -120.56746
Functional classRural Major 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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.8 US tons
Inventory rating29.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans1 (+1 approach)
Design loadHS 20
Structure length306 ft (93.3 m)
Longest span170 ft (51.8 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,083 (2022)
Projected traffic7,001 by 2038
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.8 mi (11 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Umptanum Road over Yakima River built?

It was built in 1971, making it 54 years old in 2025.

What condition is Umptanum Road over Yakima 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 November 2023.

How much traffic does Umptanum Road over Yakima River carry?

About 6,083 vehicles per day (2022 count), of which roughly 25% are trucks.

How long is Umptanum Road over Yakima River?

The structure is 306 ft (93.3 m) long with a longest span of 170 ft (51.8 m) and a deck 32 ft wide.

Who owns Umptanum Road over Yakima River?

It is owned by the County Highway Agency.