US Bridges

RD 6748 over Lake CR

Fair

Lincoln County, Montana · Silver Dollar · Structure no. 011405000000262

Built
1962
63 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
32 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

RD 6748 over Lake CR is a wood or timber stringer/multi-beam or girder carrying RD 6748 over Lake CR in Lincoln County, Montana. It was built in 1962, so it is 63 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 32 ft (9.9 m) long and 15 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
CarriesRD 6748
CrossesLake CR
LocationSilver Dollar
RouteFederal Lands Road 6748
CountyLincoln County
StateMontana
Coordinates48.03811, -115.48247
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40.3 US tons
Inventory rating31.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadOther
Structure length32 ft (9.9 m)
Longest span31 ft (9.4 m)
Deck width15 ft (4.7 m)
Roadway width13 ft (4.1 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 RD 6748 over Lake CR built?

It was built in 1962, making it 63 years old in 2025.

What condition is RD 6748 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 July 2024.

How much traffic does RD 6748 over Lake CR carry?

About 50 vehicles per day (latest count).

How long is RD 6748 over Lake CR?

The structure is 32 ft (9.9 m) long with a longest span of 31 ft (9.4 m) and a deck 15 ft wide.

Who owns RD 6748 over Lake CR?

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