US Bridges

SR 21 over San Poil River

Fair

Ferry County, Washington · 41.1 N Lincoln CO · Structure no. 0001622B0000000

Built
1932
93 years old
Condition
Fair
inspected August 2024
Type
Tee Beam
Concrete
Length
43 ft
1 main span
Daily traffic
406
2023 count
Owner
State
State Highway Agency

About this bridge

SR 21 over San Poil River is a concrete tee beam carrying SR 21 over San Poil River in Ferry County, Washington. It was built in 1932, so it is 93 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 406 vehicles a day, roughly 17% of them trucks, projected to reach 553 by 2039. The structure is 43 ft (13.1 m) long and 27 ft wide. If it were closed, the detour would be 60.3 mi (97 km).

Location

Open in Google Maps
CarriesSR 21
CrossesSan Poil River
Location41.1 N Lincoln CO
RouteState Highway 21
CountyFerry County
StateWashington
Coordinates48.47731, -118.72978
Functional classRural Major Collector

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating36 US tons
Inventory rating27.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length43 ft (13.1 m)
Longest span40 ft (12.2 m)
Deck width27 ft (8.2 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic406 (2023)
Projected traffic553 by 2039
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed60.3 mi (97 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$613,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 21 over San Poil River built?

It was built in 1932, making it 93 years old in 2025.

What condition is SR 21 over San Poil River 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 21 over San Poil River carry?

About 406 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is SR 21 over San Poil River?

The structure is 43 ft (13.1 m) long with a longest span of 40 ft (12.2 m) and a deck 27 ft wide.

Who owns SR 21 over San Poil River?

It is owned by the State Highway Agency.