Main Boulder RD over Sep I 90
Fair Condition46 years old958 vehicles/day
Location
| State | Montana |
| County | Sweet Grass |
| Location | Big Timber |
| Carries | Main Boulder RD |
| Crosses | Sep I 90 |
| Coordinates | 45.82634, -109.94860 |
Condition Ratings
| Overall Condition | Fair |
| Deck | 6 (Satisfactory) |
| Superstructure | 6 (Satisfactory) |
| Substructure | 5 (Fair) |
| Scour Critical | Not applicable |
Physical Characteristics
| Material | Steel Continuous |
| Design | Stringer/Multi-beam |
| Total Length | 395.0 ft (120.4 m) |
| Max Span | 140.1 ft (42.7 m) |
| Deck Width | 34.4 ft (10.5 m) |
| Deck Area | 1264.2 sq m |
| Main Spans | 2 |
| Year Built | 1980 |
Traffic
| Avg Daily Traffic | 958 (2023) |
| Truck Traffic | 3% |
| Lanes On Bridge | 2 |
| Lanes Under Bridge | 4 |
Inspection & Ownership
| Last Inspection | 324 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | S00298000+08841 |