I 90 over Madison River Overflow
FairGallatin County, Montana · 2.5M E Three Forks · Structure no. I00090280+00731
- Built
- 1963
- 62 years old
- Condition
- Fair
- inspected January 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 92 ft
- 2 main spans
- Daily traffic
- 9,762
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 90 over Madison River Overflow is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Madison River Overflow in Gallatin 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 9,762 vehicles a day, roughly 12% of them trucks, projected to reach 11,031 by 2043. The structure is 92 ft (27.9 m) long and 41 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 | 7 Good | Some minor problems. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 90 over Madison River Overflow built?
It was built in 1963, making it 62 years old in 2025.
What condition is I 90 over Madison River Overflow 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 January 2024.
How much traffic does I 90 over Madison River Overflow carry?
About 9,762 vehicles per day (2023 count), of which roughly 12% are trucks.
How long is I 90 over Madison River Overflow?
The structure is 92 ft (27.9 m) long with a longest span of 46 ft (13.9 m) and a deck 41 ft wide.
Who owns I 90 over Madison River Overflow?
It is owned by the State Highway Agency.