US Bridges

I 15 over S Pondera Coulee

Fair

Pondera County, Montana · 3M N Brady · Structure no. I00015331+00001

Built
1964
61 years old
Condition
Fair
inspected April 2023
Type
Culvert
Steel
Length
47 ft
2 main spans
Daily traffic
3,248
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 over S Pondera Coulee is a steel culvert carrying I 15 over S Pondera Coulee in Pondera County, Montana. It was built in 1964, so it is 61 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 3,248 vehicles a day, roughly 26% of them trucks, projected to reach 3,410 by 2043. The structure is 47 ft (14.3 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 15
CrossesS Pondera Coulee
Location3M N Brady
RouteInterstate 15
CountyPondera County
StateMontana
Coordinates48.07228, -111.85844
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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating110.1 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans2
Design loadHS 20
Structure length47 ft (14.3 m)
Longest span17 ft (5.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,248 (2023)
Projected traffic3,410 by 2043
Trucks26%
Lanes on structure4
Traffic directionTwo-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 15 over S Pondera Coulee built?

It was built in 1964, making it 61 years old in 2025.

What condition is I 15 over S Pondera Coulee 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 April 2023.

How much traffic does I 15 over S Pondera Coulee carry?

About 3,248 vehicles per day (2023 count), of which roughly 26% are trucks.

How long is I 15 over S Pondera Coulee?

The structure is 47 ft (14.3 m) long with a longest span of 17 ft (5.3 m).

Who owns I 15 over S Pondera Coulee?

It is owned by the State Highway Agency.