Irr US083 over Antelope Ck
Todd County, South Dakota · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr US083 over Antelope Ck in Todd 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 1981, making it 44 years old at the 2025 inventory.
- It carries about 2,544 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 8 of the 27 inventoried bridges in Todd County rated fair (29.6%); 7 (25.9%) 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 October 2023, on a 24-month routine inspection cycle.
- 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 → (43.3025, -100.6525)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 111 ft |
| Location | 0.1 S Jct US 18 |
| NBI structure number | 000000061300061 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 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 Todd County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Irr Bia Rte 7 over Little White River | 1972 | 1,851 | Poor |
| Main Street over Antelope Ck | 1978 | 1,400 | Fair |
| Irr US018 over Little White Rv | 1989 | 1,340 | Fair |
| Irr US018 over Trib to Oak Ck | 2005 | 1,303 | Fair |
| Irr US018 over White Horse Ck | 2016 | 1,303 | Fair |
| Irr Bia Rte 5 over Little White River | 2016 | 1,096 | Good |
All bridges nearby: Todd County, SD bridge conditions · every bridge in Todd County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.