Structure L56700002+01001 · Yellowstone County, MT
Carries Mailbox RD over Bbwa Canal 087, 7m NW Shepherd.
Set by its lowest-rated component: Deck and Superstructure and Substructure at 6 of 9.
How ratings work24 ft end to end. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.
| State | Montana |
| County | Yellowstone |
| Location | 7m NW Shepherd |
| Carries | Mailbox RD |
| Crosses | Bbwa Canal 087 |
| Coordinates | 45.98613, -108.42623 |
| Material | Steel |
| Design | Stringer/Multi-beam |
| Total Length | 24.0 ft (7.3 m) |
| Max Span | 23.3 ft (7.1 m) |
| Deck Width | 26.6 ft (8.1 m) |
| Deck Area | 59.1 sq m |
| Main Spans | 1 |
| Year Built | 1967 |
| Avg Daily Traffic | 100 (2025) |
| Truck Traffic | 3% |
| Lanes On Bridge | 2 |
| Last Inspection | January 2025 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | L56700002+01001 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.