I 90 over Clark Fork River
FairGranite County, Montana · 0.6M W Bearmouth · Structure no. I00090137+03931
- Built
- 1970
- 55 years old
- Condition
- Fair
- inspected May 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 348 ft
- 4 main spans
- Daily traffic
- 11,802
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 90 over Clark Fork River is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Clark Fork River in Granite County, Montana. It was built in 1970, so it is 55 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 11,802 vehicles a day, roughly 20% of them trucks, projected to reach 12,628 by 2043. The structure is 348 ft (106.2 m) long and 81 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 90 over Clark Fork River built?
It was built in 1970, making it 55 years old in 2025.
What condition is I 90 over Clark Fork River 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 May 2024.
How much traffic does I 90 over Clark Fork River carry?
About 11,802 vehicles per day (2023 count), of which roughly 20% are trucks.
How long is I 90 over Clark Fork River?
The structure is 348 ft (106.2 m) long with a longest span of 103 ft (31.4 m) and a deck 81 ft wide.
Who owns I 90 over Clark Fork River?
It is owned by the State Highway Agency.