US Bridges

West Fk Butte RD over Lolo CR

Fair

Missoula County, Montana · West Fk Butte · Structure no. 011603000000008

Built
1936
89 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
46 ft
2 main spans
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

West Fk Butte RD over Lolo CR is a concrete stringer/multi-beam or girder carrying West Fk Butte RD over Lolo CR in Missoula County, Montana. It was built in 1936, so it is 89 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 46 ft (14.1 m) long and 22 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
CarriesWest Fk Butte RD
CrossesLolo CR
LocationWest Fk Butte
RouteFederal Lands Road 37
CountyMissoula County
StateMontana
Coordinates46.77489, -114.43533
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating29.3 US tons
Inventory rating22.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadOther
Structure length46 ft (14.1 m)
Longest span23 ft (7 m)
Deck width22 ft (6.7 m)
Roadway width19 ft (5.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (—)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was West Fk Butte RD over Lolo CR built?

It was built in 1936, making it 89 years old in 2025.

What condition is West Fk Butte RD over Lolo CR 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 November 2023.

How much traffic does West Fk Butte RD over Lolo CR carry?

About 50 vehicles per day (latest count).

How long is West Fk Butte RD over Lolo CR?

The structure is 46 ft (14.1 m) long with a longest span of 23 ft (7 m) and a deck 22 ft wide.

Who owns West Fk Butte RD over Lolo CR?

It is owned by the U.S. Forest Service.