S 43 over Big Hole River
FairSilver Bow County, Montana · 3M W Divide · Structure no. P00046075+00661
- Built
- 1968
- 57 years old
- Condition
- Fair
- inspected March 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 304 ft
- 3 main spans
- Daily traffic
- 616
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
S 43 over Big Hole River is a prestressed concrete stringer/multi-beam or girder carrying S 43 over Big Hole River in Silver Bow County, Montana. It was built in 1968, so it is 57 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 616 vehicles a day, roughly 5% of them trucks, projected to reach 647 by 2043. The structure is 304 ft (92.7 m) long and 36 ft wide. If it were closed, the detour would be 3.7 mi (6 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 | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was S 43 over Big Hole River built?
It was built in 1968, making it 57 years old in 2025.
What condition is S 43 over Big Hole 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 March 2023.
How much traffic does S 43 over Big Hole River carry?
About 616 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is S 43 over Big Hole River?
The structure is 304 ft (92.7 m) long with a longest span of 100 ft (30.5 m) and a deck 36 ft wide.
Who owns S 43 over Big Hole River?
It is owned by the State Highway Agency.