I 90 over Boulder River
Fair Condition46 years old4,977 vehicles/day
Location
| State | Montana |
| County | Sweet Grass |
| Location | Big Timber |
| Carries | I 90 |
| Crosses | Boulder River |
| Coordinates | 45.82633, -109.94519 |
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 | Prestressed Concrete |
| Design | Stringer/Multi-beam |
| Total Length | 396.0 ft (120.7 m) |
| Max Span | 111.9 ft (34.1 m) |
| Deck Width | 44.3 ft (13.5 m) |
| Deck Area | 1629.5 sq m |
| Main Spans | 4 |
| Year Built | 1980 |
Traffic
| Avg Daily Traffic | 4,977 (2023) |
| Truck Traffic | 22% |
| Lanes On Bridge | 2 |
Inspection & Ownership
| Last Inspection | 924 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | I00090369+00271 |