US Bridges

SR 11 over Oyster Creek

Fair

Skagit County, Washington · 10.8 N JCT I-5 · Structure no. 0000825A0000000

Built
1924
101 years old
Condition
Fair
inspected August 2024
Type
Tee Beam
Concrete
Length
86 ft
3 main spans
Daily traffic
2,472
2023 count
Owner
State
State Highway Agency

About this bridge

SR 11 over Oyster Creek is a concrete tee beam carrying SR 11 over Oyster Creek in Skagit County, Washington. It was built in 1924, so it is 101 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 2,472 vehicles a day, roughly 4% of them trucks, projected to reach 3,569 by 2039. The structure is 86 ft (26.2 m) long and 29 ft wide. If it were closed, the detour would be 29.2 mi (47 km).

Location

Open in Google Maps
CarriesSR 11
CrossesOyster Creek
Location10.8 N JCT I-5
RouteState Highway 11
CountySkagit County
StateWashington
Coordinates48.61778, -122.43972
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating75 US tons
Inventory rating44 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length86 ft (26.2 m)
Longest span32 ft (9.8 m)
Deck width29 ft (8.8 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,472 (2023)
Projected traffic3,569 by 2039
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.2 mi (47 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$980,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 11 over Oyster Creek built?

It was built in 1924, making it 101 years old in 2025.

What condition is SR 11 over Oyster 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 August 2024.

How much traffic does SR 11 over Oyster Creek carry?

About 2,472 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is SR 11 over Oyster Creek?

The structure is 86 ft (26.2 m) long with a longest span of 32 ft (9.8 m) and a deck 29 ft wide.

Who owns SR 11 over Oyster Creek?

It is owned by the State Highway Agency.