US Bridges

I 90 over Willow Creek

Fair

Deer Lodge County, Montana · 2.5M N Opportunity · Structure no. I00090205+04371

Built
1978
47 years old
Condition
Fair
inspected March 2024
Type
Slab
Concrete
Length
28 ft
1 main span
Daily traffic
10,417
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Willow Creek is a concrete slab carrying I 90 over Willow Creek in Deer Lodge County, Montana. It was built in 1978, so it is 47 years old, younger 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 10,417 vehicles a day, roughly 24% of them trucks, projected to reach 11,198 by 2043. The structure is 28 ft (8.4 m) long and 150 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 90
CrossesWillow Creek
Location2.5M N Opportunity
RouteInterstate 90
CountyDeer Lodge County
StateMontana
Coordinates46.12639, -112.79807
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43 US tons
Inventory rating33 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length28 ft (8.4 m)
Longest span25 ft (7.6 m)
Deck width150 ft (45.7 m)
Roadway width80 ft (24.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,417 (2023)
Projected traffic11,198 by 2043
Trucks24%
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 90 over Willow Creek built?

It was built in 1978, making it 47 years old in 2025.

What condition is I 90 over Willow Creek 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 March 2024.

How much traffic does I 90 over Willow Creek carry?

About 10,417 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 90 over Willow Creek?

The structure is 28 ft (8.4 m) long with a longest span of 25 ft (7.6 m) and a deck 150 ft wide.

Who owns I 90 over Willow Creek?

It is owned by the State Highway Agency.