US Bridges

1-LANE Road over South Fork Spring Creek

Fair

Carbon County, Montana · 8 Miles SW of Red Lodge · Structure no. 010802000001074

Built
1979
46 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
28 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

1-LANE Road over South Fork Spring Creek is a steel stringer/multi-beam or girder carrying 1-LANE Road over South Fork Spring Creek in Carbon County, Montana. It was built in 1979, so it is 46 years old, younger 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 28 ft (8.4 m) long and 13 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
Carries1-LANE Road
CrossesSouth Fork Spring Creek
Location8 Miles SW of Red Lodge
RouteFederal Lands Road 2379
CountyCarbon County
StateMontana
Coordinates45.08453, -109.33529
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 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 adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating57.1 US tons
Inventory rating44 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans1
Design loadHS 20
Structure length28 ft (8.4 m)
Longest span26 ft (7.9 m)
Deck width13 ft (4 m)
Roadway width12 ft (3.7 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 byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 1-LANE Road over South Fork Spring Creek built?

It was built in 1979, making it 46 years old in 2025.

What condition is 1-LANE Road over South Fork Spring 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 May 2023.

How much traffic does 1-LANE Road over South Fork Spring Creek carry?

About 50 vehicles per day (latest count).

How long is 1-LANE Road over South Fork Spring Creek?

The structure is 28 ft (8.4 m) long with a longest span of 26 ft (7.9 m) and a deck 13 ft wide.

Who owns 1-LANE Road over South Fork Spring Creek?

It is owned by the U.S. Forest Service and maintained by the County Highway Agency.