Structure 177050 · Harrison County, IA
Carries 315th ST over Mosquito Creek, 078412003.
222 ft end to end, longest span 90 ft: about 3 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. 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 through truss.
| State | Iowa |
| County | Harrison |
| Location | 078412003 |
| Carries | 315th ST |
| Crosses | Mosquito Creek |
| Coordinates | 41.54968, -95.57784 |
| Material | Steel |
| Design | Truss - Thru |
| Total Length | 222.1 ft (67.7 m) |
| Max Span | 89.9 ft (27.4 m) |
| Deck Width | 16.7 ft (5.1 m) |
| Deck Area | 345.3 sq m |
| Main Spans | 2 |
| Year Built | 1930 (reconstructed 1993) |
| Avg Daily Traffic | 20 (2022) |
| Lanes On Bridge | 2 |
| Last Inspection | December 2024 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is possibly eligible (requires evaluation) |
| Scour Critical | Unknown |
| Structure Number | 000000000177050 |
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.