IRR - S 313 over Bighorn River
Fair Condition68 years old899 vehicles/day
Location
| State | Montana |
| County | Big Horn |
| Location | 7m SW Hardin |
| Carries | IRR - S 313 |
| Crosses | Bighorn River |
| Coordinates | 45.64409, -107.65773 |
Condition Ratings
| Overall Condition | Fair |
| Deck | 6 (Satisfactory) |
| Superstructure | 6 (Satisfactory) |
| Substructure | 6 (Satisfactory) |
| Channel/Waterway | 6 (Satisfactory) |
| Scour Critical | 7 — Countermeasures installed |
Physical Characteristics
| Material | Steel Continuous |
| Design | Girder and Floorbeam |
| Total Length | 575.8 ft (175.5 m) |
| Max Span | 160.1 ft (48.8 m) |
| Deck Width | 26.9 ft (8.2 m) |
| Deck Area | 1439.1 sq m |
| Main Spans | 4 |
| Year Built | 1958 |
Traffic
| Avg Daily Traffic | 899 (2023) |
| Truck Traffic | 17% |
| Lanes On Bridge | 2 |
Inspection & Ownership
| Last Inspection | 723 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | S00313008+03271 |