US Bridges

337 Boulder/Basin over Basin Creek

Fair

Lincoln County, Montana · 6 Miles from JCT W/92 · Structure no. 011404000001008

Built
1968
57 years old, rebuilt 1994
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
24 ft
1 main span
Daily traffic
50
1994 count
Owner
Federal
U.S. Forest Service

About this bridge

337 Boulder/Basin over Basin Creek is a wood or timber stringer/multi-beam or girder carrying 337 Boulder/Basin over Basin Creek in Lincoln County, Montana. It was built in 1968 and reconstructed in 1994, 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 24 ft (7.3 m) long and 15 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

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Carries337 Boulder/Basin
CrossesBasin Creek
Location6 Miles from JCT W/92
RouteFederal Lands Road 337-2
CountyLincoln County
StateMontana
Coordinates48.87915, -115.48359
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating49.3 US tons
Inventory rating37.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadOther
Structure length24 ft (7.3 m)
Longest span23 ft (7 m)
Deck width15 ft (4.7 m)
Roadway width13 ft (4.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (1994)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 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 337 Boulder/Basin over Basin Creek built?

It was built in 1968, making it 57 years old in 2025. It was reconstructed in 1994.

What condition is 337 Boulder/Basin over Basin Creek 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 337 Boulder/Basin over Basin Creek carry?

About 50 vehicles per day (1994 count).

How long is 337 Boulder/Basin over Basin Creek?

The structure is 24 ft (7.3 m) long with a longest span of 23 ft (7 m) and a deck 15 ft wide.

Who owns 337 Boulder/Basin over Basin Creek?

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