30410 390 Ave over Mosquito Ck
Charles Mix County, South Dakota · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 30410 390 Ave over Mosquito Ck in Charles Mix County, South Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1941, making it 84 years old at the 2025 inventory.
- It carries about 48 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 24 of the 103 inventoried bridges in Charles Mix County rated poor (23.3%); 24 (23.3%) 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 → (42.97834, -98.38551)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 8 | Very good condition |
| Superstructure | 5 | Fair condition |
| Substructure | 3 | Serious condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 24 ft |
| Location | 7.1S 4.8W of Wagner |
| NBI structure number | 000000012462361 |
| Condition class | Poor |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Charles Mix County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SD045 over Drainage Channel | 1994 | 3,934 | Good |
| SD044 over Platte Ck | 1964 | 2,420 | Fair |
| SD044 over Castalia Ck | 1963 | 1,538 | Good |
| Irr US018 over Saint Francis Bay | 2023 | 1,494 | Good |
| Irr SD050 over Trib Choteau Ck | 2020 | 1,329 | Good |
| Old Irr SD050 over Ck | 1940 | 1,329 | Fair |
All bridges nearby: Charles Mix County, SD bridge conditions · every bridge in Charles Mix County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.