US Bridges

I 15 over Little Prickly Pear CR

Fair

Lewis and Clark County, Montana · 9M S Wolf Creek · Structure no. I00015218+04032

Built
1965
60 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
652 ft
2 main spans
Daily traffic
2,403
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 over Little Prickly Pear CR is a steel stringer/multi-beam or girder carrying I 15 over Little Prickly Pear CR in Lewis and Clark County, Montana. It was built in 1965, so it is 60 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 2,403 vehicles a day, roughly 23% of them trucks, projected to reach 2,607 by 2043. The structure is 652 ft (198.8 m) long and 31 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 15
CrossesLittle Prickly Pear CR
Location9M S Wolf Creek
RouteInterstate 15
CountyLewis and Clark County
StateMontana
Coordinates46.9115, -112.11529
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating45.7 US tons
Inventory rating31.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2 (+9 approach)
Design loadHS 20
Structure length652 ft (198.8 m)
Longest span91 ft (27.7 m)
Deck width31 ft (9.4 m)
Roadway width29 ft (8.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,403 (2023)
Projected traffic2,607 by 2043
Trucks23%
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.8 million
NavigationNo navigation control on waterway

Frequently asked questions

When was I 15 over Little Prickly Pear CR built?

It was built in 1965, making it 60 years old in 2025.

What condition is I 15 over Little Prickly Pear CR 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 2024.

How much traffic does I 15 over Little Prickly Pear CR carry?

About 2,403 vehicles per day (2023 count), of which roughly 23% are trucks.

How long is I 15 over Little Prickly Pear CR?

The structure is 652 ft (198.8 m) long with a longest span of 91 ft (27.7 m) and a deck 31 ft wide.

Who owns I 15 over Little Prickly Pear CR?

It is owned by the State Highway Agency.