473 Avenue over South Fork Whetstone Rv
Grant County, South Dakota · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 473 Avenue over South Fork Whetstone Rv in Grant County, South Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1942 and reconstructed in 1965, making it 83 years old at the 2025 inventory.
- It carries about 25 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 38 of the 205 inventoried bridges in Grant County rated poor (18.5%); 38 (18.5%) are rated poor.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (45.22589, -96.74173)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 4 | Poor condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 35 ft |
| Location | 5W & 0.2N Milbank |
| NBI structure number | 000000026240068 |
| Condition class | Poor |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Grant County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Irr I029 over Indian Rv | 1976 | 6,600 | Fair |
| US012 over Whetstone Rv Div Channel | 1955 | 3,765 | Fair |
| Irr I029 S over 146 St | 1977 | 3,650 | Fair |
| Irr I029 N over 146 St | 1977 | 3,650 | Good |
| Irr I029 S over 149 St (fas 6266) | 1976 | 3,650 | Fair |
| Irr I029 N over 149 St (fas 6266) | 1976 | 3,650 | Fair |
All bridges nearby: Grant County, SD bridge conditions · every bridge in Grant County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.