239TH St. over Rock Ck
Miner County, South Dakota · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 239TH St. over Rock Ck in Miner County, South Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1910, making it 115 years old at the 2025 inventory.
- It carries about 5 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 19 of the 63 inventoried bridges in Miner County rated poor (30.2%); 19 (30.2%) 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 → (43.92167, -97.65994)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 4 | Poor condition |
| Superstructure | 3 | Serious condition |
| Substructure | 3 | Serious condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 26 ft |
| Location | 6S & 6.5W Howard |
| NBI structure number | 000000049095190 |
| Condition class | Poor |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Miner County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SD034 over West Fork Vermillion Rv | 1987 | 2,168 | Good |
| SD034 over Rock Ck | 1986 | 1,462 | Good |
| SD034 over Ck | 2023 | 970 | Good |
| SD034 over Ck | 2023 | 970 | Good |
| SD025 over West Fork Vermillion Rv | 1953 | 762 | Fair |
| SD025 over Rock Ck | 1976 | 485 | Fair |
All bridges nearby: Miner County, SD bridge conditions · every bridge in Miner County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.