US Bridges

SR 11 over Gn RY Colony Creek

Fair

Skagit County, Washington · 9.2 N JCT I-5 · Structure no. 0001496A0000000

Built
1931
94 years old
Condition
Fair
inspected July 2023
Type
Tee Beam
Concrete Continuous
Length
883 ft
18 main spans
Daily traffic
2,472
2023 count
Owner
State
State Highway Agency

About this bridge

SR 11 over Gn RY Colony Creek is a concrete continuous tee beam carrying SR 11 over Gn RY Colony Creek in Skagit County, Washington. It was built in 1931, so it is 94 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 2,472 vehicles a day, roughly 4% of them trucks, projected to reach 3,569 by 2039. The structure is 883 ft (269.1 m) long and 34 ft wide. If it were closed, the detour would be 29.2 mi (47 km).

Location

Open in Google Maps
CarriesSR 11
CrossesGn RY Colony Creek
Location9.2 N JCT I-5
RouteState Highway 11
CountySkagit County
StateWashington
Coordinates48.59806, -122.42225
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.
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 inspectionJuly 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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.8 US tons
Inventory rating25.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans18
Design loadH 15
Structure length883 ft (269.1 m)
Longest span66 ft (20.1 m)
Deck width34 ft (10.5 m)
Roadway width27 ft (8.2 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 and pedestrian
CrossesRailroad and waterway
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$11.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 11 over Gn RY Colony Creek built?

It was built in 1931, making it 94 years old in 2025.

What condition is SR 11 over Gn RY Colony 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 July 2023.

How much traffic does SR 11 over Gn RY Colony Creek carry?

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

How long is SR 11 over Gn RY Colony Creek?

The structure is 883 ft (269.1 m) long with a longest span of 66 ft (20.1 m) and a deck 34 ft wide.

Who owns SR 11 over Gn RY Colony Creek?

It is owned by the State Highway Agency.