US Bridges

Old HWY 10 W over Powder River 040

Fair

Prairie County, Montana · 6M SW Terry · Structure no. L40004006+02001

Built
1945
80 years old
Condition
Fair
inspected July 2023
Type
Truss - Thru
Steel Continuous
Length
636 ft
3 main spans
Daily traffic
507
2023 count
Owner
State
State Highway Agency

About this bridge

Old HWY 10 W over Powder River 040 is a steel continuous truss - thru carrying Old HWY 10 W over Powder River 040 in Prairie County, Montana. It was built in 1945, so it is 80 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 507 vehicles a day, roughly 3% of them trucks, projected to reach 540 by 2043. The structure is 636 ft (193.8 m) long and 30 ft wide. If it were closed, the detour would be 28 mi (45 km).

Location

Open in Google Maps
CarriesOld HWY 10 W
CrossesPowder River 040
Location6M SW Terry
RouteState Highway 81020
CountyPrairie County
StateMontana
Coordinates46.73726, -105.42852
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
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 rating23 US tons
Inventory rating14 US tons

Structure

Structure typeTruss - Thru
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadH 15
Structure length636 ft (193.8 m)
Longest span204 ft (62.1 m)
Deck width30 ft (9.2 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deck15 ft (4.6 m)

Traffic and service

Average daily traffic507 (2023)
Projected traffic540 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed28 mi (45 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.4 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Old HWY 10 W over Powder River 040 built?

It was built in 1945, making it 80 years old in 2025.

What condition is Old HWY 10 W over Powder River 040 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 Old HWY 10 W over Powder River 040 carry?

About 507 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Old HWY 10 W over Powder River 040?

The structure is 636 ft (193.8 m) long with a longest span of 204 ft (62.1 m) and a deck 30 ft wide.

Who owns Old HWY 10 W over Powder River 040?

It is owned by the State Highway Agency.