US Bridges

I 90 over Int Two Mile-St Regis R

Fair

Mineral County, Montana · 3.7M W St. Regis · Structure no. I00090030+01171

Built
1981
44 years old, rebuilt 2005
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
286 ft
3 main spans
Daily traffic
4,056
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Int Two Mile-St Regis R is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Int Two Mile-St Regis R in Mineral County, Montana. It was built in 1981 and reconstructed in 2005, so it is 44 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 4,056 vehicles a day, roughly 24% of them trucks, projected to reach 4,258 by 2043. The structure is 286 ft (87.2 m) long and 44 ft wide.

Location

Open in Google Maps
CarriesI 90
CrossesInt Two Mile-St Regis R
Location3.7M W St. Regis
RouteInterstate 90
CountyMineral County
StateMontana
Coordinates47.29531, -115.16468
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.5 US tons
Inventory rating26.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length286 ft (87.2 m)
Longest span101 ft (30.8 m)
Deck width44 ft (13.4 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,056 (2023)
Projected traffic4,258 by 2043
Trucks24%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway and waterway
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was I 90 over Int Two Mile-St Regis R built?

It was built in 1981, making it 44 years old in 2025. It was reconstructed in 2005.

What condition is I 90 over Int Two Mile-St Regis R 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 September 2023.

How much traffic does I 90 over Int Two Mile-St Regis R carry?

About 4,056 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 90 over Int Two Mile-St Regis R?

The structure is 286 ft (87.2 m) long with a longest span of 101 ft (30.8 m) and a deck 44 ft wide.

Who owns I 90 over Int Two Mile-St Regis R?

It is owned by the State Highway Agency.