US Bridges

I 94 over Powder River

Fair

Prairie County, Montana · 7M SW Terry · Structure no. I00094169+07742

Built
1971
54 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
539 ft
5 main spans
Daily traffic
2,137
2023 count
Owner
State
State Highway Agency

About this bridge

I 94 over Powder River is a steel continuous stringer/multi-beam or girder carrying I 94 over Powder River in Prairie County, Montana. It was built in 1971, so it is 54 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 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 2,137 vehicles a day, roughly 27% of them trucks, projected to reach 2,244 by 2043. The structure is 539 ft (164.4 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 94
CrossesPowder River
Location7M SW Terry
RouteInterstate 94
CountyPrairie County
StateMontana
Coordinates46.73253, -105.41947
Functional classRural Principal Arterial - Interstate

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating28.9 US tons
Inventory rating22.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length539 ft (164.4 m)
Longest span165 ft (50.3 m)
Deck width44 ft (13.4 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,137 (2023)
Projected traffic2,244 by 2043
Trucks27%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I 94 over Powder River built?

It was built in 1971, making it 54 years old in 2025.

What condition is I 94 over Powder 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 July 2023.

How much traffic does I 94 over Powder River carry?

About 2,137 vehicles per day (2023 count), of which roughly 27% are trucks.

How long is I 94 over Powder River?

The structure is 539 ft (164.4 m) long with a longest span of 165 ft (50.3 m) and a deck 44 ft wide.

Who owns I 94 over Powder River?

It is owned by the State Highway Agency.