US Bridges

Twelve Mile RD over Colville River

FairPosted for load

Stevens County, Washington · 00.35 W JCT SR 395 · Structure no. 084771000000000

Built
1929
96 years old, rebuilt 1966
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
77 ft
1 main span
Daily traffic
251
2024 count
Owner
County
County Highway Agency

About this bridge

Twelve Mile RD over Colville River is a steel stringer/multi-beam or girder carrying Twelve Mile RD over Colville River in Stevens County, Washington. It was built in 1929 and reconstructed in 1966, so it is 96 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. Its operating status is: posted for load restriction.

It carries about 251 vehicles a day, roughly 5% of them trucks, projected to reach 600 by 2037. The structure is 77 ft (23.5 m) long and 29 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesTwelve Mile RD
CrossesColville River
Location00.35 W JCT SR 395
RouteCounty Highway 34890
CountyStevens County
StateWashington
Coordinates48.40311, -117.85399
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
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating21.1 US tons
Inventory rating16.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHS 20
Structure length77 ft (23.5 m)
Longest span76 ft (23.2 m)
Deck width29 ft (8.8 m)
Roadway width25 ft (7.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic251 (2024)
Projected traffic600 by 2037
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$3.1 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Twelve Mile RD over Colville River built?

It was built in 1929, making it 96 years old in 2025. It was reconstructed in 1966.

What condition is Twelve Mile RD over Colville 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 October 2023.

How much traffic does Twelve Mile RD over Colville River carry?

About 251 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Twelve Mile RD over Colville River?

The structure is 77 ft (23.5 m) long with a longest span of 76 ft (23.2 m) and a deck 29 ft wide.

Who owns Twelve Mile RD over Colville River?

It is owned by the County Highway Agency.