US Bridges

SR 20 over Ship Hbr/Guemes Channel

Poor

Skagit County, Washington · 7.8N on SR20 Spur · Structure no. 0008985A0000000

Built
1959
66 years old, rebuilt 1994
Condition
Poor
inspected August 2024
Type
Movable - Lift
Steel
Length
105 ft
1 main span
Daily traffic
3,227
2010 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Ship Hbr/Guemes Channel is a steel movable - lift carrying SR 20 over Ship Hbr/Guemes Channel in Skagit County, Washington. It was built in 1959 and reconstructed in 1994, 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 3,227 vehicles a day, roughly 2% of them trucks, projected to reach 5,576 by 2036. The structure is 105 ft (32 m) long and 24 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

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be 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 rating36 US tons
Inventory rating20.9 US tons

Structure

Structure typeMovable - Lift
MaterialSteel
DeckClosed grating
Main spans1
Design loadH 15
Structure length105 ft (32 m)
Longest span80 ft (24.4 m)
Deck width24 ft (7.3 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deck16 ft (4.9 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$1.3 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. It was reconstructed in 1994.

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

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. 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 105 ft (32 m) long with a longest span of 80 ft (24.4 m) and a deck 24 ft wide.

Who owns SR 20 over Ship Hbr/Guemes Channel?

It is owned by the State Highway Agency.