US Bridges

Mountain Loop HWY over Dutch Creek

Fair

Snohomish County, Washington · 8.0 SE Darrington · Structure no. 087030000000000

Built
2003
22 years old
Condition
Fair
inspected May 2024
Type
Tee Beam
Prestressed Concrete
Length
108 ft
1 main span
Daily traffic
383
2023 count
Owner
County
County Highway Agency

About this bridge

Mountain Loop HWY over Dutch Creek is a prestressed concrete tee beam carrying Mountain Loop HWY over Dutch Creek in Snohomish County, Washington. It was built in 2003, so it is 22 years old, younger 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 383 vehicles a day, roughly 10% of them trucks, projected to reach 800 by 2044. The structure is 108 ft (32.8 m) long and 30 ft wide. If it were closed, the detour would be 93.8 mi (151 km).

Location

Open in Google Maps
CarriesMountain Loop HWY
CrossesDutch Creek
Location8.0 SE Darrington
RouteCounty Highway 98960
CountySnohomish County
StateWashington
Coordinates48.17911, -121.48704
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating77.9 US tons
Inventory rating43 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 25 or greater
Structure length108 ft (32.8 m)
Longest span100 ft (30.6 m)
Deck width30 ft (9.1 m)
Roadway width27 ft (8.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic383 (2023)
Projected traffic800 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed93.8 mi (151 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$4.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mountain Loop HWY over Dutch Creek built?

It was built in 2003, making it 22 years old in 2025.

What condition is Mountain Loop HWY over Dutch 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 May 2024.

How much traffic does Mountain Loop HWY over Dutch Creek carry?

About 383 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Mountain Loop HWY over Dutch Creek?

The structure is 108 ft (32.8 m) long with a longest span of 100 ft (30.6 m) and a deck 30 ft wide.

Who owns Mountain Loop HWY over Dutch Creek?

It is owned by the County Highway Agency.