US Bridges

SR 20 over Lost Creek

Fair

Pend Oreille County, Washington · 5.3 E JCT SR 31 · Structure no. 0001810A0000000

Built
1934
91 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
64 ft
4 main spans
Daily traffic
1,093
2023 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Lost Creek is a wood or timber stringer/multi-beam or girder carrying SR 20 over Lost Creek in Pend Oreille County, Washington. It was built in 1934, so it is 91 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.

It carries about 1,093 vehicles a day, roughly 16% of them trucks, projected to reach 1,346 by 2039. The structure is 64 ft (19.5 m) long and 27 ft wide. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
CarriesSR 20
CrossesLost Creek
Location5.3 E JCT SR 31
RouteState Highway 20
CountyPend Oreille County
StateWashington
Coordinates48.61297, -117.36608
Functional classRural Minor 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42 US tons
Inventory rating28 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans4
Design loadH 15
Structure length64 ft (19.5 m)
Longest span15 ft (4.6 m)
Deck width27 ft (8.2 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,093 (2023)
Projected traffic1,346 by 2039
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 km)
TollOn a free road
National Highway SystemNo

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 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 20 over Lost Creek built?

It was built in 1934, making it 91 years old in 2025.

What condition is SR 20 over Lost 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 August 2024.

How much traffic does SR 20 over Lost Creek carry?

About 1,093 vehicles per day (2023 count), of which roughly 16% are trucks.

How long is SR 20 over Lost Creek?

The structure is 64 ft (19.5 m) long with a longest span of 15 ft (4.6 m) and a deck 27 ft wide.

Who owns SR 20 over Lost Creek?

It is owned by the State Highway Agency.