US Bridges

No Data Entered over Middle Fork Rock CR

Fair

Granite County, Montana · At Junction to Moose Lake · Structure no. 010903000000026

Built
1956
69 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
51 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

No Data Entered over Middle Fork Rock CR is a wood or timber stringer/multi-beam or girder carrying No Data Entered over Middle Fork Rock CR in Granite County, Montana. It was built in 1956, so it is 69 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 51 ft (15.6 m) long and 15 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
CarriesNo Data Entered
CrossesMiddle Fork Rock CR
LocationAt Junction to Moose Lake
RouteFederal Lands Road 80
CountyGranite County
StateMontana
Coordinates46.067, -113.53947
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.1 US tons
Inventory rating28.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length51 ft (15.6 m)
Longest span49 ft (14.9 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.4 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 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 Middle Fork Rock CR built?

It was built in 1956, making it 69 years old in 2025.

What condition is No Data Entered over Middle 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 2023.

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

About 50 vehicles per day (latest count).

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

The structure is 51 ft (15.6 m) long with a longest span of 49 ft (14.9 m) and a deck 15 ft wide.

Who owns No Data Entered over Middle Fork Rock CR?

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