US Bridges

SR 11 over Samish River

Fair

Skagit County, Washington · 2.9 N JCT I-5 · Structure no. 0000397A0000000

Built
1920
105 years old
Condition
Fair
inspected October 2024
Type
Arch - Deck
Concrete
Length
75 ft
1 main span
Daily traffic
4,112
2023 count
Owner
State
State Highway Agency

About this bridge

SR 11 over Samish River is a concrete arch - deck carrying SR 11 over Samish River in Skagit County, Washington. It was built in 1920, so it is 105 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 4,112 vehicles a day, roughly 7% of them trucks, projected to reach 6,029 by 2039. The structure is 75 ft (22.9 m) long and 26 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSR 11
CrossesSamish River
Location2.9 N JCT I-5
RouteState Highway 11
CountySkagit County
StateWashington
Coordinates48.51668, -122.37838
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
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
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 rating51.5 US tons
Inventory rating39.7 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length75 ft (22.9 m)
Longest span75 ft (22.9 m)
Deck width26 ft (7.9 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,112 (2023)
Projected traffic6,029 by 2039
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 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$1.1 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 11 over Samish River built?

It was built in 1920, making it 105 years old in 2025.

What condition is SR 11 over Samish 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 October 2024.

How much traffic does SR 11 over Samish River carry?

About 4,112 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is SR 11 over Samish River?

The structure is 75 ft (22.9 m) long with a longest span of 75 ft (22.9 m) and a deck 26 ft wide.

Who owns SR 11 over Samish River?

It is owned by the State Highway Agency.