US Bridges

No Data Entered over West Fork Rock CR

Fair

Granite County, Montana · West Fork Rock CR · Structure no. 010903000000049

Built
1969
56 years old, rebuilt 1991
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
36 ft
1 main span
Daily traffic
40
2018 count
Owner
Federal
U.S. Forest Service

About this bridge

No Data Entered over West Fork Rock CR is a wood or timber stringer/multi-beam or girder carrying No Data Entered over West Fork Rock CR in Granite County, Montana. It was built in 1969 and reconstructed in 1991, so it is 56 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 40 vehicles a day, projected to reach 60 by 2045. The structure is 36 ft (11.1 m) long and 16 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
CarriesNo Data Entered
CrossesWest Fork Rock CR
LocationWest Fork Rock CR
RouteFederal Lands Road 5070
CountyGranite County
StateMontana
Coordinates46.19865, -113.70245
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 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 adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.4 US tons
Inventory rating38.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length36 ft (11.1 m)
Longest span35 ft (10.7 m)
Deck width16 ft (4.8 m)
Roadway width15 ft (4.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (2018)
Projected traffic60 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 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 No Data Entered over West Fork Rock CR built?

It was built in 1969, making it 56 years old in 2025. It was reconstructed in 1991.

What condition is No Data Entered over West Fork Rock 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 August 2024.

How much traffic does No Data Entered over West Fork Rock CR carry?

About 40 vehicles per day (2018 count).

How long is No Data Entered over West Fork Rock CR?

The structure is 36 ft (11.1 m) long with a longest span of 35 ft (10.7 m) and a deck 16 ft wide.

Who owns No Data Entered over West Fork Rock CR?

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