I 90 over Jr Grade Sep
FairPowell County, Montana · 6.2M N Deer Lodge · Structure no. I00090180+04301
- Built
- 1961
- 64 years old, rebuilt 1978
- Condition
- Fair
- inspected May 2024
- Type
- Slab
- Concrete
- Length
- 23 ft
- 1 main span
- Daily traffic
- 10,463
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 90 over Jr Grade Sep is a concrete slab carrying I 90 over Jr Grade Sep in Powell County, Montana. It was built in 1961 and reconstructed in 1978, so it is 64 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 10,463 vehicles a day, roughly 20% of them trucks, projected to reach 11,300 by 2043. The structure is 23 ft (6.9 m) long and 124 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 90 over Jr Grade Sep built?
It was built in 1961, making it 64 years old in 2025. It was reconstructed in 1978.
What condition is I 90 over Jr Grade Sep 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 Jr Grade Sep carry?
About 10,463 vehicles per day (2023 count), of which roughly 20% are trucks.
How long is I 90 over Jr Grade Sep?
The structure is 23 ft (6.9 m) long with a longest span of 21 ft (6.5 m) and a deck 124 ft wide.
Who owns I 90 over Jr Grade Sep?
It is owned by the State Highway Agency.