US Bridges

I 15 over Int Spring Creek-Rr

Fair

Lewis and Clark County, Montana · 7M S Wolf Creek · Structure no. I00015219+02181

Built
1964
61 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
539 ft
10 main spans
Daily traffic
2,555
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 over Int Spring Creek-Rr is a prestressed concrete stringer/multi-beam or girder carrying I 15 over Int Spring Creek-Rr in Lewis and Clark 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 2,555 vehicles a day, roughly 21% of them trucks, projected to reach 2,771 by 2043. The structure is 539 ft (164.4 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
CrossesInt Spring Creek-Rr
Location7M S Wolf Creek
RouteInterstate 15
CountyLewis and Clark County
StateMontana
Coordinates46.92153, -112.12262
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
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating36 US tons
Inventory rating17 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans10
Design loadHS 20
Structure length539 ft (164.4 m)
Longest span72 ft (21.8 m)
Deck width31 ft (9.6 m)
Roadway width30 ft (9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,555 (2023)
Projected traffic2,771 by 2043
Trucks21%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway, waterway and railroad
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 Int Spring Creek-Rr built?

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

What condition is I 15 over Int Spring Creek-Rr 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 December 2024.

How much traffic does I 15 over Int Spring Creek-Rr carry?

About 2,555 vehicles per day (2023 count), of which roughly 21% are trucks.

How long is I 15 over Int Spring Creek-Rr?

The structure is 539 ft (164.4 m) long with a longest span of 72 ft (21.8 m) and a deck 31 ft wide.

Who owns I 15 over Int Spring Creek-Rr?

It is owned by the State Highway Agency.