US Bridges

I 90 over Sep Hump Creek Road

Fair

Sweet Grass County, Montana · 1.2M W Reed Point · Structure no. I00090391+00401

Built
1963
62 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
102 ft
3 main spans
Daily traffic
5,423
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Sep Hump Creek Road is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Sep Hump Creek Road in Sweet Grass County, Montana. It was built in 1963, so it is 62 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 5,423 vehicles a day, roughly 20% of them trucks, projected to reach 5,829 by 2043. The structure is 102 ft (31.1 m) long and 47 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 90
CrossesSep Hump Creek Road
Location1.2M W Reed Point
RouteInterstate 90
CountySweet Grass County
StateMontana
Coordinates45.70522, -109.56358
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.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66 US tons
Inventory rating44 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length102 ft (31.1 m)
Longest span36 ft (11 m)
Deck width47 ft (14.3 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,423 (2023)
Projected traffic5,829 by 2043
Trucks20%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 90 over Sep Hump Creek Road built?

It was built in 1963, making it 62 years old in 2025.

What condition is I 90 over Sep Hump Creek Road 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 October 2023.

How much traffic does I 90 over Sep Hump Creek Road carry?

About 5,423 vehicles per day (2023 count), of which roughly 20% are trucks.

How long is I 90 over Sep Hump Creek Road?

The structure is 102 ft (31.1 m) long with a longest span of 36 ft (11 m) and a deck 47 ft wide.

Who owns I 90 over Sep Hump Creek Road?

It is owned by the State Highway Agency.