US 12 over Big Porcupine Overflow
Fair Condition38 years old214 vehicles/day
Location
| State | Montana |
| County | Rosebud |
| Location | 13m NW Forsyth |
| Carries | US 12 |
| Crosses | Big Porcupine Overflow |
| Coordinates | 46.36687, -106.90499 |
Condition Ratings
| Overall Condition | Fair |
| Deck | 7 (Good) |
| Superstructure | 7 (Good) |
| Substructure | 6 (Satisfactory) |
| Channel/Waterway | 6 (Satisfactory) |
| Scour Critical | 8 — Stable, low risk |
Physical Characteristics
| Material | Concrete Continuous |
| Design | Slab |
| Total Length | 79.1 ft (24.1 m) |
| Max Span | 29.9 ft (9.1 m) |
| Deck Width | 34.4 ft (10.5 m) |
| Deck Area | 253.1 sq m |
| Main Spans | 3 |
| Year Built | 1988 |
Traffic
| Avg Daily Traffic | 214 (2023) |
| Truck Traffic | 15% |
| Lanes On Bridge | 2 |
Inspection & Ownership
| Last Inspection | 824 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | P00014257+04721 |