US Bridges

I 15 over Pondera Canal

Fair

Pondera County, Montana · 9M N Conrad · Structure no. I00015347+08141

Built
1972
53 years old
Condition
Fair
inspected February 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
73 ft
1 main span
Daily traffic
1,510
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 over Pondera Canal is a prestressed concrete stringer/multi-beam or girder carrying I 15 over Pondera Canal in Pondera County, Montana. It was built in 1972, so it is 53 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 1,510 vehicles a day, roughly 28% of them trucks, projected to reach 1,585 by 2043. The structure is 73 ft (22.3 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 15
CrossesPondera Canal
Location9M N Conrad
RouteInterstate 15
CountyPondera County
StateMontana
Coordinates48.30061, -111.93597
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length73 ft (22.3 m)
Longest span70 ft (21.3 m)
Deck width44 ft (13.5 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,510 (2023)
Projected traffic1,585 by 2043
Trucks28%
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 15 over Pondera Canal built?

It was built in 1972, making it 53 years old in 2025.

What condition is I 15 over Pondera Canal 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 February 2024.

How much traffic does I 15 over Pondera Canal carry?

About 1,510 vehicles per day (2023 count), of which roughly 28% are trucks.

How long is I 15 over Pondera Canal?

The structure is 73 ft (22.3 m) long with a longest span of 70 ft (21.3 m) and a deck 44 ft wide.

Who owns I 15 over Pondera Canal?

It is owned by the State Highway Agency.