US Bridges

RD 7583 over W Fork Swamp CR

Fair

Sanders County, Montana · Bemish CR · Structure no. 011605000000148

Built
1970
55 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
25 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

RD 7583 over W Fork Swamp CR is a wood or timber stringer/multi-beam or girder carrying RD 7583 over W Fork Swamp CR in Sanders 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 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 25 ft (7.7 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 7583
CrossesW Fork Swamp CR
LocationBemish CR
RouteFederal Lands Road 7583
CountySanders County
StateMontana
Coordinates47.46007, -115.04271
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionJuly 2023
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating29.3 US tons
Inventory rating22.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length25 ft (7.7 m)
Longest span23 ft (7 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-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 7583 over W Fork Swamp CR built?

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

What condition is RD 7583 over W Fork Swamp 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 2023.

How much traffic does RD 7583 over W Fork Swamp CR carry?

About 50 vehicles per day (latest count).

How long is RD 7583 over W Fork Swamp CR?

The structure is 25 ft (7.7 m) long with a longest span of 23 ft (7 m) and a deck 15 ft wide.

Who owns RD 7583 over W Fork Swamp CR?

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