US Bridges

SR 20 over Harney Channel

Fair

San Juan County, Washington · On Orcas Island · Structure no. 0013202A0000000

Built
1979
46 years old, rebuilt 1987
Condition
Fair
inspected September 2024
Type
Movable - Lift
Steel
Length
105 ft
1 main span
Daily traffic
2,150
2010 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Harney Channel is a steel movable - lift carrying SR 20 over Harney Channel in San Juan County, Washington. It was built in 1979 and reconstructed in 1987, so it is 46 years old, younger 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 2,150 vehicles a day, roughly 11% of them trucks, projected to reach 3,010 by 2034. The structure is 105 ft (32 m) long and 21 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSR 20
CrossesHarney Channel
LocationOn Orcas Island
RouteState Highway 20
CountySan Juan County
StateWashington
Coordinates48.59744, -122.94369
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
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 rating36 US tons
Inventory rating20.9 US tons

Structure

Structure typeMovable - Lift
MaterialSteel
DeckOpen grating
Main spans1
Design loadHS 20
Structure length105 ft (32 m)
Longest span80 ft (24.4 m)
Deck width21 ft (6.4 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deck16 ft (4.9 m)

Traffic and service

Average daily traffic2,150 (2010)
Projected traffic3,010 by 2034
Trucks11%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed98.8 mi (159 km)
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$798,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 20 over Harney Channel built?

It was built in 1979, making it 46 years old in 2025. It was reconstructed in 1987.

What condition is SR 20 over Harney 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 September 2024.

How much traffic does SR 20 over Harney Channel carry?

About 2,150 vehicles per day (2010 count), of which roughly 11% are trucks.

How long is SR 20 over Harney Channel?

The structure is 105 ft (32 m) long with a longest span of 80 ft (24.4 m) and a deck 21 ft wide.

Who owns SR 20 over Harney Channel?

It is owned by the State Highway Agency.