479 Avenue over South Fork Whetstone Rv
Grant County, South Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 479 Avenue over South Fork Whetstone Rv in Grant County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 2003, making it 22 years old at the 2025 inventory.
- It carries about 40 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 100 of the 205 inventoried bridges in Grant County rated good (48.8%); 38 (18.5%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated fair in the 2024 inventory and is now good (superstructure 6 to 7).
- Its most recent inspection on record is dated September 2024, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (45.23285, -96.61901)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 6 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete tee beam |
| Length | about 71 ft |
| Location | 1E & 0.6N Milbank |
| NBI structure number | 000000026300064 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
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.