SD075 over Thunder Butte Ck
Perkins County, South Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- SD075 over Thunder Butte Ck in Perkins County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 1994, making it 31 years old at the 2025 inventory.
- It carries about 192 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 32 of the 60 inventoried bridges in Perkins County rated good (53.3%); 3 (5.0%) 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 → (45.53311, -102.6428)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 7 | Good condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 31 ft |
| Location | 0.2 N Jct Sd 20 |
| NBI structure number | 000000053150289 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Perkins County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SD073 over East Flat Ck | 2018 | 663 | Good |
| SD073 over Flat Ck | 1995 | 663 | Good |
| SD073 over Grand Rv | 1995 | 663 | Fair |
| SD073 over Moreau Rv | 2016 | 425 | Good |
| SD073 over Flint Rock Ck | 2016 | 425 | Good |
| SD073 over Thunder Butte Ck | 2005 | 423 | Good |
All bridges nearby: Perkins County, SD bridge conditions · every bridge in Perkins County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.