US Bridges

IRR - S 13 over Missouri River

Fair

Roosevelt County, Montana · 6M SE Wolf Point · Structure no. P00025046+05391

Built
1998
27 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
626 ft
3 main spans
Daily traffic
1,163
2023 count
Owner
State
State Highway Agency

About this bridge

IRR - S 13 over Missouri River is a steel continuous stringer/multi-beam or girder carrying IRR - S 13 over Missouri River in Roosevelt County, Montana. It was built in 1998, so it is 27 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 6 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 1,163 vehicles a day, roughly 13% of them trucks, projected to reach 1,221 by 2043. The structure is 626 ft (190.7 m) long and 38 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesIRR - S 13
CrossesMissouri River
Location6M SE Wolf Point
RouteState Highway 13
CountyRoosevelt County
StateMontana
Coordinates48.06642, -105.53546
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.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53 US tons
Inventory rating41 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length626 ft (190.7 m)
Longest span236 ft (72 m)
Deck width38 ft (11.7 m)
Roadway width35 ft (10.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,163 (2023)
Projected traffic1,221 by 2043
Trucks13%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was IRR - S 13 over Missouri River built?

It was built in 1998, making it 27 years old in 2025.

What condition is IRR - S 13 over Missouri 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 May 2024.

How much traffic does IRR - S 13 over Missouri River carry?

About 1,163 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is IRR - S 13 over Missouri River?

The structure is 626 ft (190.7 m) long with a longest span of 236 ft (72 m) and a deck 38 ft wide.

Who owns IRR - S 13 over Missouri River?

It is owned by the State Highway Agency.