US Bridges

I 90 over Hogan Slough

Fair

Yellowstone County, Montana · Billings · Structure no. I00090445+04541

Built
1959
66 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
82 ft
2 main spans
Daily traffic
15,229
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Hogan Slough is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Hogan Slough in Yellowstone County, Montana. It was built in 1959, so it is 66 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 15,229 vehicles a day, roughly 8% of them trucks, projected to reach 15,990 by 2043. The structure is 82 ft (25 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 90
CrossesHogan Slough
LocationBillings
RouteInterstate 90
CountyYellowstone County
StateMontana
Coordinates45.74831, -108.57041
Functional classUrban 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.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.1 US tons
Inventory rating45 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length82 ft (25 m)
Longest span41 ft (12.5 m)
Deck width42 ft (12.7 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,229 (2023)
Projected traffic15,990 by 2043
Trucks8%
Lanes on structure2
Traffic directionOne-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 Hogan Slough built?

It was built in 1959, making it 66 years old in 2025.

What condition is I 90 over Hogan Slough 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 Hogan Slough carry?

About 15,229 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is I 90 over Hogan Slough?

The structure is 82 ft (25 m) long with a longest span of 41 ft (12.5 m) and a deck 42 ft wide.

Who owns I 90 over Hogan Slough?

It is owned by the State Highway Agency.