US Bridges

IRR - S 13 over W Fork Poplar River

Fair

Roosevelt County, Montana · 18M S Scobey · Structure no. P00032034+02881

Built
2005
20 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
310 ft
3 main spans
Daily traffic
229
2023 count
Owner
State
State Highway Agency

About this bridge

IRR - S 13 over W Fork Poplar River is a prestressed concrete stringer/multi-beam or girder carrying IRR - S 13 over W Fork Poplar River in Roosevelt County, Montana. It was built in 2005, so it is 20 years old, younger 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 229 vehicles a day, roughly 11% of them trucks, projected to reach 240 by 2043. The structure is 310 ft (94.5 m) long and 34 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesIRR - S 13
CrossesW Fork Poplar River
Location18M S Scobey
RouteState Highway 13
CountyRoosevelt County
StateMontana
Coordinates48.54914, -105.42986
Functional classRural Minor Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54 US tons
Inventory rating42 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length310 ft (94.5 m)
Longest span103 ft (31.5 m)
Deck width34 ft (10.3 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic229 (2023)
Projected traffic240 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$290,000
NavigationNo navigation control on waterway

Frequently asked questions

When was IRR - S 13 over W Fork Poplar River built?

It was built in 2005, making it 20 years old in 2025.

What condition is IRR - S 13 over W Fork Poplar River 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 IRR - S 13 over W Fork Poplar River carry?

About 229 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is IRR - S 13 over W Fork Poplar River?

The structure is 310 ft (94.5 m) long with a longest span of 103 ft (31.5 m) and a deck 34 ft wide.

Who owns IRR - S 13 over W Fork Poplar River?

It is owned by the State Highway Agency.