US Bridges

N.Fk Blackft RD over N Fk Blackfoot Riv

Fair

Powell County, Montana · No Data Entered · Structure no. 011606000000103

Built
1960
65 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
143 ft
2 main spans
Daily traffic
40
Owner
Federal
U.S. Forest Service

About this bridge

N.Fk Blackft RD over N Fk Blackfoot Riv is a prestressed concrete continuous stringer/multi-beam or girder carrying N.Fk Blackft RD over N Fk Blackfoot Riv in Powell County, Montana. It was built in 1960, so it is 65 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 40 vehicles a day, projected to reach 60 by 2045. The structure is 143 ft (43.6 m) long and 25 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

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CarriesN.Fk Blackft RD
CrossesN Fk Blackfoot Riv
LocationNo Data Entered
RouteFederal Lands Road 5550
CountyPowell County
StateMontana
Coordinates47.10278, -112.96102
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating45.3 US tons
Inventory rating35.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length143 ft (43.6 m)
Longest span70 ft (21.3 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (—)
Projected traffic60 by 2045
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 N.Fk Blackft RD over N Fk Blackfoot Riv built?

It was built in 1960, making it 65 years old in 2025.

What condition is N.Fk Blackft RD over N Fk Blackfoot Riv 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 October 2024.

How much traffic does N.Fk Blackft RD over N Fk Blackfoot Riv carry?

About 40 vehicles per day (latest count).

How long is N.Fk Blackft RD over N Fk Blackfoot Riv?

The structure is 143 ft (43.6 m) long with a longest span of 70 ft (21.3 m) and a deck 25 ft wide.

Who owns N.Fk Blackft RD over N Fk Blackfoot Riv?

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