US Bridges

S 141 over Stockpass-Drainage

Fair

Powell County, Montana · 2M SE Helmsville · Structure no. P00041024+08001

Built
1965
60 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
22 ft
1 main span
Daily traffic
1,408
2023 count
Owner
State
State Highway Agency

About this bridge

S 141 over Stockpass-Drainage is a wood or timber stringer/multi-beam or girder carrying S 141 over Stockpass-Drainage in Powell County, Montana. It was built in 1965, so it is 60 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 6 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 1,408 vehicles a day, roughly 9% of them trucks, projected to reach 1,654 by 2043. The structure is 22 ft (6.7 m) long and 33 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesS 141
CrossesStockpass-Drainage
Location2M SE Helmsville
RouteState Highway 141
CountyPowell County
StateMontana
Coordinates46.84261, -112.90045
Functional classRural Minor Arterial

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating43 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadUnknown
Structure length22 ft (6.7 m)
Longest span19 ft (5.8 m)
Deck width33 ft (10.1 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,408 (2023)
Projected traffic1,654 by 2043
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 S 141 over Stockpass-Drainage built?

It was built in 1965, making it 60 years old in 2025.

What condition is S 141 over Stockpass-Drainage 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 2023.

How much traffic does S 141 over Stockpass-Drainage carry?

About 1,408 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is S 141 over Stockpass-Drainage?

The structure is 22 ft (6.7 m) long with a longest span of 19 ft (5.8 m) and a deck 33 ft wide.

Who owns S 141 over Stockpass-Drainage?

It is owned by the State Highway Agency.