Diversion Dam Road over Inlet Canal
Butte County, South Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Diversion Dam Road over Inlet Canal in Butte County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1906 and reconstructed in 1989, making it 119 years old at the 2025 inventory.
- It carries about 1 vehicles a day (traffic count year 2017).
- It is one of 46 of the 142 inventoried bridges in Butte County rated good (32.4%); 20 (14.1%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated fair in the 2024 inventory and is now good (deck 6 to 7).
- Its most recent inspection on record is dated September 2023, on a 24-month routine inspection cycle.
- 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 → (44.69071, -103.83093)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete channel beam |
| Length | about 80 ft |
| Location | 1.3 mi NE Belle Fourche |
| NBI structure number | 10-110-361 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Butte County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US085 over Hay Ck | 1963 | 15,432 | Fair |
| US085 over Belle Fourche Rv | 1958 | 10,476 | Fair |
| SD034 over Willow Ck | 1939 | 3,961 | Fair |
| SD034 over Redwater Rv | 1992 | 3,547 | Fair |
| SD034 over Redwater Canal | 1964 | 3,547 | Good |
| SD034 over False Bottom Ck | 1992 | 3,547 | Fair |
All bridges nearby: Butte County, SD bridge conditions · every bridge in Butte County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.