366 Avenue over North Scalp Ck
Gregory County, South Dakota · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 366 Avenue over North Scalp Ck in Gregory County, South Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 4 (poor condition) on the 0-9 scale.
- It was built in 2015, making it 10 years old at the 2025 inventory.
- It carries about 36 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 5 of the 51 inventoried bridges in Gregory County rated poor (9.8%); 5 (9.8%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated good in the 2024 inventory and is now poor (culvert 8 to 4).
- Its most recent inspection on record is dated July 2024, on a 24-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 → (43.12034, -98.86317)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 8 | 4 | Poor condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 21 ft |
| Location | 4.2E & 2.8N Bonesteel |
| NBI structure number | 000000027342262 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 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 Gregory County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| 345 Avenue over South Fork Whetstone Ck | 2001 | 560 | Good |
| SD047 over Ck | 1957 | 552 | Fair |
| SD047 over Ck | 1957 | 552 | Fair |
| SD044 over Bull Ck | 1971 | 540 | Good |
| SD044 over Lone Tree Ck | 1971 | 540 | Fair |
| SD044 over Dixon Ck | 1971 | 540 | Fair |
All bridges nearby: Gregory County, SD bridge conditions · every bridge in Gregory County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.