446A Avenue over Blue Dog Lake
Day County, South Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 446A Avenue over Blue Dog Lake in Day County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 8 (very good condition) on the 0-9 scale.
- It was built in 2023, making it 2 years old at the 2025 inventory.
- It carries about 852 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 15 of the 34 inventoried bridges in Day County rated good (44.1%); 9 (26.5%) are rated poor.
- 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 → (45.34856, -97.27654)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 8 | Very good condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 49 ft |
| Location | 1.5E & 0.5N of Waubay |
| NBI structure number | 000000019345165 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Day County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SD027 over Antelope Ck | 1970 | 428 | Fair |
| SD027 over Ck | 1970 | 428 | Fair |
| 130TH Street over Creek | 1935 | 385 | Fair |
| 130TH Street over Creek | 1930 | 376 | Good |
| 128TH Street over Creek | 2011 | 307 | Good |
| 128TH Street over Creek | 1993 | 307 | Fair |
All bridges nearby: Day County, SD bridge conditions · every bridge in Day County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.