US Bridges

SR 20 over Canoe Pass

Fair

Skagit County, Washington · 0.2 E Island CO · Structure no. 0001929B0000000

Built
1935
90 years old
Condition
Fair
inspected February 2023
Type
Truss - Deck
Steel Continuous
Length
511 ft
3 main spans
Daily traffic
18,797
2023 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Canoe Pass is a steel continuous truss - deck carrying SR 20 over Canoe Pass in Skagit County, Washington. It was built in 1935, so it is 90 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 18,797 vehicles a day, roughly 6% of them trucks, projected to reach 29,201 by 2039. The structure is 511 ft (155.8 m) long and 30 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSR 20
CrossesCanoe Pass
Location0.2 E Island CO
RouteState Highway 20
CountySkagit County
StateWashington
Coordinates48.40833, -122.64486
Functional classRural Principal Arterial - Other

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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
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 rating28.2 US tons
Inventory rating21.8 US tons

Structure

Structure typeTruss - Deck
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+3 approach)
Design loadH 15
Structure length511 ft (155.8 m)
Longest span350 ft (106.7 m)
Deck width30 ft (9.2 m)
Roadway width22 ft (6.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,797 (2023)
Projected traffic29,201 by 2039
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkSTRAHNET connector

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$8.3 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 20 over Canoe Pass built?

It was built in 1935, making it 90 years old in 2025.

What condition is SR 20 over Canoe Pass 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 February 2023.

How much traffic does SR 20 over Canoe Pass carry?

About 18,797 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 20 over Canoe Pass?

The structure is 511 ft (155.8 m) long with a longest span of 350 ft (106.7 m) and a deck 30 ft wide.

Who owns SR 20 over Canoe Pass?

It is owned by the State Highway Agency.