US 191 FH 42 over West Gallatin River
FairGallatin County, Montana · 17M SE Big Sky · Structure no. P00050032+07581
- Built
- 1959
- 66 years old
- Condition
- Fair
- inspected July 2023
- Type
- Tee Beam
- Concrete Continuous
- Length
- 122 ft
- 3 main spans
- Daily traffic
- 2,325
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US 191 FH 42 over West Gallatin River is a concrete continuous tee beam carrying US 191 FH 42 over West Gallatin River in Gallatin 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 2,325 vehicles a day, roughly 11% of them trucks, projected to reach 2,441 by 2043. The structure is 122 ft (37.2 m) long and 33 ft wide. If it were closed, the detour would be 123.7 mi (199 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. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US 191 FH 42 over West Gallatin River built?
It was built in 1959, making it 66 years old in 2025.
What condition is US 191 FH 42 over West Gallatin 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 July 2023.
How much traffic does US 191 FH 42 over West Gallatin River carry?
About 2,325 vehicles per day (2023 count), of which roughly 11% are trucks.
How long is US 191 FH 42 over West Gallatin River?
The structure is 122 ft (37.2 m) long with a longest span of 45 ft (13.7 m) and a deck 33 ft wide.
Who owns US 191 FH 42 over West Gallatin River?
It is owned by the State Highway Agency.