US Bridges

SR 20 over Harney Channel

GoodPosted for load

San Juan County, Washington · On Orcas Island · Structure no. 0006120A0000000

Built
1959
66 years old, rebuilt 1987
Condition
Good
inspected September 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
107 ft
6 main spans
Daily traffic
2,322
2010 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Harney Channel is a wood or timber stringer/multi-beam or girder carrying SR 20 over Harney Channel in San Juan County, Washington. It was built in 1959 and reconstructed in 1987, 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. Its operating status is: posted for load restriction.

It carries about 2,322 vehicles a day, roughly 2% of them trucks, projected to reach 4,012 by 2036. The structure is 107 ft (32.6 m) long and 29 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
Coordinates48.59756, -122.94378
Functional classUrban Other Principal Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
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 rating40 US tons
Inventory rating28 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans6
Design loadH 15
Structure length107 ft (32.6 m)
Longest span17 ft (5.2 m)
Deck width29 ft (8.7 m)
Roadway width19 ft (5.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,322 (2010)
Projected traffic4,012 by 2036
Trucks2%
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$1.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 20 over Harney Channel built?

It was built in 1959, making it 66 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 good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2024.

How much traffic does SR 20 over Harney Channel carry?

About 2,322 vehicles per day (2010 count), of which roughly 2% are trucks.

How long is SR 20 over Harney Channel?

The structure is 107 ft (32.6 m) long with a longest span of 17 ft (5.2 m) and a deck 29 ft wide.

Who owns SR 20 over Harney Channel?

It is owned by the State Highway Agency.