US Bridges

SR 20 over Ship Hbr/Guemes Channel

FairPosted for load

Skagit County, Washington · 7.8N on SR20 Spur · Structure no. 0008985D0000000

Built
1959
66 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
158 ft
10 main spans
Daily traffic
3,227
2010 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Ship Hbr/Guemes Channel is a wood or timber stringer/multi-beam or girder carrying SR 20 over Ship Hbr/Guemes Channel in Skagit County, Washington. It was built in 1959, so it is 66 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. Its operating status is: posted for load restriction.

It carries about 3,227 vehicles a day, roughly 2% of them trucks, projected to reach 5,576 by 2036. The structure is 158 ft (48.2 m) long and 50 ft wide.

Location

Open in Google Maps
CarriesSR 20
CrossesShip Hbr/Guemes Channel
Location7.8N on SR20 Spur
RouteState Highway 20
CountySkagit County
StateWashington
Coordinates48.50667, -122.67667
Functional classUrban Other Principal Arterial

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
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 rating33 US tons
Inventory rating23 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans10
Design loadH 15
Structure length158 ft (48.2 m)
Longest span19 ft (5.8 m)
Deck width50 ft (15.2 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deck16 ft (4.8 m)

Traffic and service

Average daily traffic3,227 (2010)
Projected traffic5,576 by 2036
Trucks2%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollToll bridge
National Highway SystemYes

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$4.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 20 over Ship Hbr/Guemes Channel built?

It was built in 1959, making it 66 years old in 2025.

What condition is SR 20 over Ship Hbr/Guemes Channel 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 20 over Ship Hbr/Guemes Channel carry?

About 3,227 vehicles per day (2010 count), of which roughly 2% are trucks.

How long is SR 20 over Ship Hbr/Guemes Channel?

The structure is 158 ft (48.2 m) long with a longest span of 19 ft (5.8 m) and a deck 50 ft wide.

Who owns SR 20 over Ship Hbr/Guemes Channel?

It is owned by the State Highway Agency.