US Bridges

N.Fk Blackft RD over Lake CR

Fair

Powell County, Montana · Copper Blackfoot · Structure no. 011606000000102

Built
1964
61 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
91 ft
3 main spans
Daily traffic
40
Owner
Federal
U.S. Forest Service

About this bridge

N.Fk Blackft RD over Lake CR is a wood or timber stringer/multi-beam or girder carrying N.Fk Blackft RD over Lake CR in Powell County, Montana. It was built in 1964, so it is 61 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 91 ft (27.6 m) long and 25 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

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CarriesN.Fk Blackft RD
CrossesLake CR
LocationCopper Blackfoot
RouteFederal Lands Road 5550
CountyPowell County
StateMontana
Coordinates47.11557, -112.97082
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
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 geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.7 US tons
Inventory rating35.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadHS 25 or greater
Structure length91 ft (27.6 m)
Longest span32 ft (9.8 m)
Deck width25 ft (7.7 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 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 N.Fk Blackft RD over Lake CR built?

It was built in 1964, making it 61 years old in 2025.

What condition is N.Fk Blackft RD over Lake 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 October 2024.

How much traffic does N.Fk Blackft RD over Lake CR carry?

About 40 vehicles per day (latest count).

How long is N.Fk Blackft RD over Lake CR?

The structure is 91 ft (27.6 m) long with a longest span of 32 ft (9.8 m) and a deck 25 ft wide.

Who owns N.Fk Blackft RD over Lake CR?

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