Irr US012 over Claymore Ck
Corson County, South Dakota · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr US012 over Claymore Ck in Corson County, South Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1958, making it 67 years old at the 2025 inventory.
- It carries about 1,378 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 4 of the 49 inventoried bridges in Corson County rated poor (8.2%); 4 (8.2%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2024, on a 12-month routine inspection cycle.
- 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 → (45.55865, -100.51579)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 4 | Poor condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 251 ft |
| Location | 2.4 W Walworth Co Line |
| NBI structure number | 000000016725271 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 12 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 Corson County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Irr US012 over Deep Bank Ck | 1965 | 1,091 | Fair |
| Irr US012 over Br Snake Ck | 1965 | 1,091 | Fair |
| Irr US012 over Snake Ck | 1966 | 1,091 | Fair |
| Irr SD020 over Ck | 2000 | 956 | Good |
| Irr SD063 over Oak Ck | 1980 | 864 | Fair |
| Irr SD063 over Ck | 1980 | 864 | Good |
All bridges nearby: Corson County, SD bridge conditions · every bridge in Corson County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.