Thunder Butte Road over Moreau Rv
Ziebach County, South Dakota · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Thunder Butte Road over Moreau Rv in Ziebach County, South Dakota, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1969, making it 56 years old at the 2025 inventory.
- It carries about 143 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 20 of the 30 inventoried bridges in Ziebach County rated fair (66.7%); 3 (10.0%) 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 July 2024, on a 12-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (45.21604, -101.69418)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 333 ft |
| Location | 11.2 N 4.2 W Dupree |
| NBI structure number | 000000069158178 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Ziebach County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Irr US212 over Ck | 1954 | 1,291 | Fair |
| Irr US212 over Bear Ck | 1954 | 1,130 | Fair |
| Irr US212 over Bear Ck | 1955 | 1,083 | Fair |
| Irr Bia Rte 6 over Ash Creek | 1968 | 814 | Good |
| Irr SD063 over Rudy Ck Tributary | 1994 | 590 | Fair |
| Irr SD063 over Rudey Ck | 1993 | 590 | Fair |
All bridges nearby: Ziebach County, SD bridge conditions · every bridge in Ziebach County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.