Main Boulder RD over Boulder River
Good Condition51 years old529 vehicles/day
Location
| State | Montana |
| County | Sweet Grass |
| Location | 8m S Big Timber |
| Carries | Main Boulder RD |
| Crosses | Boulder River |
| Coordinates | 45.72329, -109.99680 |
Condition Ratings
| Overall Condition | Good |
| Deck | 7 (Good) |
| Superstructure | 7 (Good) |
| Substructure | 7 (Good) |
| Channel/Waterway | 7 (Good) |
| Scour Critical | 5 — Stable for scour |
Physical Characteristics
| Material | Prestressed Concrete |
| Design | Stringer/Multi-beam |
| Total Length | 206.0 ft (62.8 m) |
| Max Span | 70.9 ft (21.6 m) |
| Deck Width | 34.4 ft (10.5 m) |
| Deck Area | 659.4 sq m |
| Main Spans | 3 |
| Year Built | 1975 |
Traffic
| Avg Daily Traffic | 529 (2023) |
| Truck Traffic | 5% |
| 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 | S00298008+05001 |