US Bridges

I 90 over Int Beavertail

Fair

Missoula County, Montana · 7.4M W Bearmouth · Structure no. I00090130+04302

Built
1972
53 years old, rebuilt 1992
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
125 ft
3 main spans
Daily traffic
5,901
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Int Beavertail is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Int Beavertail in Missoula County, Montana. It was built in 1972 and reconstructed in 1992, 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 5,901 vehicles a day, roughly 20% of them trucks, projected to reach 6,314 by 2043. The structure is 125 ft (38.1 m) long and 43 ft wide.

CarriesI 90
CrossesInt Beavertail
Location7.4M W Bearmouth
RouteInterstate 90
StateMontana
Coordinates46.72557, -113.57589
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50 US tons
Inventory rating34 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length125 ft (38.1 m)
Longest span46 ft (14 m)
Deck width43 ft (13.2 m)
Roadway width42 ft (12.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,901 (2023)
Projected traffic6,314 by 2043
Trucks20%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed—
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 90 over Int Beavertail built?

It was built in 1972, making it 53 years old in 2025. It was reconstructed in 1992.

What condition is I 90 over Int Beavertail 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 2024.

How much traffic does I 90 over Int Beavertail carry?

About 5,901 vehicles per day (2023 count), of which roughly 20% are trucks.

How long is I 90 over Int Beavertail?

The structure is 125 ft (38.1 m) long with a longest span of 46 ft (14 m) and a deck 43 ft wide.

Who owns I 90 over Int Beavertail?

It is owned by the State Highway Agency.