SD258 over Snow Ck
Aurora County, South Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- SD258 over Snow Ck in Aurora County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 1950, making it 75 years old at the 2025 inventory.
- It carries about 798 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 25 of the 61 inventoried bridges in Aurora County rated good (41.0%); 7 (11.5%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (good), but component ratings moved: culvert 8 to 7.
- Its most recent inspection on record is dated September 2024, on a 48-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 → (43.71026, -98.48478)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 8 | 7 | Good condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 24 ft |
| Location | 0.5N & E I90 Interchange |
| NBI structure number | 00000000215D154 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 48 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 Aurora County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I090 over Ck | 1965 | 9,890 | Fair |
| I090 W over Platte Ck | 1964 | 4,425 | Fair |
| I090 E over Platte Ck | 1964 | 4,425 | Fair |
| US281 over I090 | 1965 | 1,694 | Fair |
| US281 over Ck | 2007 | 1,434 | Good |
| US281 over West Br Firesteel Ck | 1959 | 1,284 | Fair |
All bridges nearby: Aurora County, SD bridge conditions · every bridge in Aurora County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.