4100 W over Big Lost River
Fair Condition49 years old50 vehicles/day
Location
| State | Idaho |
| County | Custer |
| Location | 2.5 S. 5.2 E. Mackay |
| Carries | 4100 W |
| Crosses | Big Lost River |
| Coordinates | 43.87036, -113.51256 |
Condition Ratings
| Overall Condition | Fair |
| Deck | 7 (Good) |
| Superstructure | 7 (Good) |
| Substructure | 5 (Fair) |
| Channel/Waterway | 4 (Poor) |
| Scour Critical | 4 — Foundations need monitoring |
Physical Characteristics
| Material | Prestressed Concrete |
| Design | Tee Beam |
| Total Length | 69.9 ft (21.3 m) |
| Max Span | 67.9 ft (20.7 m) |
| Deck Width | 27.9 ft (8.5 m) |
| Deck Area | 181.1 sq m |
| Main Spans | 1 |
| Year Built | 1977 |
Traffic
| Avg Daily Traffic | 50 (2023) |
| Truck Traffic | 10% |
| Lanes On Bridge | 2 |
Inspection & Ownership
| Last Inspection | October 2023 |
| Inspection Frequency | Every 24 months |
| Owner | Other Local Agencies |
| Historical Significance | Historical significance is not determined |
| Structure Number | 000000000031710 |