US Bridges

No Data Entered over Middle Fork Rock CR

Fair

Granite County, Montana · Before Kaiser Lake · Structure no. 010903000000053

Built
1965
60 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
51 ft
1 main span
Daily traffic
40
2018 count
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 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 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 51 ft (15.4 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
LocationBefore Kaiser Lake
RouteFederal Lands Road 5121
CountyGranite County
StateMontana
Coordinates46.0963, -113.5066
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating50 US tons
Inventory rating38.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 25 or greater
Structure length51 ft (15.4 m)
Longest span49 ft (14.9 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.3 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 Middle Fork Rock CR built?

It was built in 1965, making it 60 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 2024.

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

About 40 vehicles per day (2018 count).

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

The structure is 51 ft (15.4 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.