US Bridges

North Ave W over Bitterroot River 010

FairPosted for load

Missoula County, Montana · W Missoula · Structure no. L32101000+01001

Built
1935
90 years old, rebuilt 1964
Condition
Fair
inspected June 2023
Type
Truss - Thru
Steel
Length
346 ft
2 main spans
Daily traffic
3,627
2023 count
Owner
County
County Highway Agency

About this bridge

North Ave W over Bitterroot River 010 is a steel truss - thru carrying North Ave W over Bitterroot River 010 in Missoula County, Montana. It was built in 1935 and reconstructed in 1964, so it is 90 years old, older than the Montana average of 47 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 3,627 vehicles a day, roughly 3% of them trucks, projected to reach 3,863 by 2043. The structure is 346 ft (105.4 m) long and 16 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesNorth Ave W
CrossesBitterroot River 010
LocationW Missoula
RouteCounty Highway 32101
CountyMissoula County
StateMontana
Coordinates46.85313, -114.0979
Functional classRural Local

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.
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 inspectionJune 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating25 US tons
Inventory rating15 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckCorrugated steel
Main spans2 (+2 approach)
Design loadUnknown
Structure length346 ft (105.4 m)
Longest span180 ft (54.9 m)
Deck width16 ft (5 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deck14 ft (4.3 m)

Traffic and service

Average daily traffic3,627 (2023)
Projected traffic3,863 by 2043
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$722,000
NavigationNo navigation control on waterway

Frequently asked questions

When was North Ave W over Bitterroot River 010 built?

It was built in 1935, making it 90 years old in 2025. It was reconstructed in 1964.

What condition is North Ave W over Bitterroot River 010 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 June 2023.

How much traffic does North Ave W over Bitterroot River 010 carry?

About 3,627 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is North Ave W over Bitterroot River 010?

The structure is 346 ft (105.4 m) long with a longest span of 180 ft (54.9 m) and a deck 16 ft wide.

Who owns North Ave W over Bitterroot River 010?

It is owned by the County Highway Agency.