US 12 over Big Porcupine Creek
GoodRosebud County, Montana · 13M NW Forsyth · Structure no. P00014257+02111
- Built
- 2004
- 21 years old
- Condition
- Good
- inspected August 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 143 ft
- 3 main spans
- Daily traffic
- 214
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US 12 over Big Porcupine Creek is a prestressed concrete stringer/multi-beam or girder carrying US 12 over Big Porcupine Creek in Rosebud County, Montana. It was built in 2004, so it is 21 years old, younger than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 214 vehicles a day, roughly 15% of them trucks, projected to reach 225 by 2043. The structure is 143 ft (43.6 m) long and 34 ft wide. If it were closed, the detour would be 123.7 mi (199 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 7 Good | Some minor problems. |
| 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 US 12 over Big Porcupine Creek built?
It was built in 2004, making it 21 years old in 2025.
What condition is US 12 over Big Porcupine Creek in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2024.
How much traffic does US 12 over Big Porcupine Creek carry?
About 214 vehicles per day (2023 count), of which roughly 15% are trucks.
How long is US 12 over Big Porcupine Creek?
The structure is 143 ft (43.6 m) long with a longest span of 48 ft (14.5 m) and a deck 34 ft wide.
Who owns US 12 over Big Porcupine Creek?
It is owned by the State Highway Agency.