US Bridges

SR 20 over Snow Creek

Fair

Jefferson County, Washington · 0.1 E JCT US 101 · Structure no. 0002571A0000000

Built
1940
85 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
104 ft
6 main spans
Daily traffic
4,980
2023 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Snow Creek is a wood or timber stringer/multi-beam or girder carrying SR 20 over Snow Creek in Jefferson County, Washington. It was built in 1940, so it is 85 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 4,980 vehicles a day, roughly 8% of them trucks, projected to reach 6,817 by 2039. The structure is 104 ft (31.7 m) long and 37 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSR 20
CrossesSnow Creek
Location0.1 E JCT US 101
RouteState Highway 20
CountyJefferson County
StateWashington
Coordinates47.98783, -122.88575
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating39 US tons
Inventory rating26 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans6
Design loadH 15
Structure length104 ft (31.7 m)
Longest span17 ft (5.2 m)
Deck width37 ft (11.3 m)
Roadway width35 ft (10.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,980 (2023)
Projected traffic6,817 by 2039
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
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$1.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 20 over Snow Creek built?

It was built in 1940, making it 85 years old in 2025.

What condition is SR 20 over Snow Creek 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 October 2024.

How much traffic does SR 20 over Snow Creek carry?

About 4,980 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is SR 20 over Snow Creek?

The structure is 104 ft (31.7 m) long with a longest span of 17 ft (5.2 m) and a deck 37 ft wide.

Who owns SR 20 over Snow Creek?

It is owned by the State Highway Agency.