SD1804 over Blue Blanket Ck
FairWalworth County, South Dakota · 2.5 S JCT US 12 · Structure no. 000000065072059
- Built
- 1961
- 64 years old
- Condition
- Fair
- inspected December 2024
- Type
- Slab
- Concrete Continuous
- Length
- 129 ft
- 5 main spans
- Daily traffic
- 272
- 2024 count
- Owner
- State
- State Highway Agency
About this bridge
SD1804 over Blue Blanket Ck is a concrete continuous slab carrying SD1804 over Blue Blanket Ck in Walworth County, South Dakota. It was built in 1961, so it is 64 years old, older than the South Dakota average of 48.9 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 272 vehicles a day, roughly 6% of them trucks, projected to reach 429 by 2044. The structure is 129 ft (39.2 m) long and 28 ft wide. If it were closed, the detour would be 98.8 mi (159 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was SD1804 over Blue Blanket Ck built?
It was built in 1961, making it 64 years old in 2025.
What condition is SD1804 over Blue Blanket Ck in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in December 2024.
How much traffic does SD1804 over Blue Blanket Ck carry?
About 272 vehicles per day (2024 count), of which roughly 6% are trucks.
How long is SD1804 over Blue Blanket Ck?
The structure is 129 ft (39.2 m) long with a longest span of 26 ft (7.9 m) and a deck 28 ft wide.
Who owns SD1804 over Blue Blanket Ck?
It is owned by the State Highway Agency.