US Bridges

W Main ST over Bitterroot River

Fair

Ravalli County, Montana · W Hamilton · Structure no. S00531005+04001

Built
1968
57 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
304 ft
4 main spans
Daily traffic
2,746
2023 count
Owner
State
State Highway Agency

About this bridge

W Main ST over Bitterroot River is a prestressed concrete stringer/multi-beam or girder carrying W Main ST over Bitterroot River in Ravalli County, Montana. It was built in 1968, so it is 57 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.

It carries about 2,746 vehicles a day, projected to reach 2,883 by 2043. The structure is 304 ft (92.8 m) long and 46 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesW Main ST
CrossesBitterroot River
LocationW Hamilton
RouteState Highway 5302
CountyRavalli County
StateMontana
Coordinates46.24686, -114.17748
Functional classUrban 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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53 US tons
Inventory rating31 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 15
Structure length304 ft (92.8 m)
Longest span102 ft (31.1 m)
Deck width46 ft (14.1 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,746 (2023)
Projected traffic2,883 by 2043
Trucks0%
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

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was W Main ST over Bitterroot River built?

It was built in 1968, making it 57 years old in 2025.

What condition is W Main ST over Bitterroot 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 April 2024.

How much traffic does W Main ST over Bitterroot River carry?

About 2,746 vehicles per day (2023 count).

How long is W Main ST over Bitterroot River?

The structure is 304 ft (92.8 m) long with a longest span of 102 ft (31.1 m) and a deck 46 ft wide.

Who owns W Main ST over Bitterroot River?

It is owned by the State Highway Agency.