US Bridges

2-LANE Road over Rock Creek

Poor

Carbon County, Montana · No Data Entered · Structure no. 010802000000204

Built
1970
55 years old
Condition
Poor
inspected August 2024
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

2-LANE Road over Rock Creek is a wood or timber stringer/multi-beam or girder carrying 2-LANE Road over Rock Creek in Carbon County, Montana. It was built in 1970, so it is 55 years old, older than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 50 vehicles a day, projected to reach 75 by 2045. The structure is 51 ft (15.5 m) long and 26 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
Carries2-LANE Road
CrossesRock Creek
LocationNo Data Entered
RouteFederal Lands Road 2346
CountyCarbon County
StateMontana
Coordinates45.08228, -109.37625
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
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 rating29.3 US tons
Inventory rating22.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadH 20
Structure length51 ft (15.5 m)
Longest span49 ft (14.9 m)
Deck width26 ft (7.8 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (—)
Projected traffic75 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 2-LANE Road over Rock Creek built?

It was built in 1970, making it 55 years old in 2025.

What condition is 2-LANE Road over Rock Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2024.

How much traffic does 2-LANE Road over Rock Creek carry?

About 50 vehicles per day (latest count).

How long is 2-LANE Road over Rock Creek?

The structure is 51 ft (15.5 m) long with a longest span of 49 ft (14.9 m) and a deck 26 ft wide.

Who owns 2-LANE Road over Rock Creek?

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