Stae Highway 1806 over Oahe Dam Spillway
PoorStanley County, South Dakota · 5 Miles No. of Ft. Pierre · Structure no. 59-360-228
- Built
- 1963
- 62 years old
- Condition
- Poor
- inspected September 2023
- Type
- Girder and Floorbeam System
- Steel Continuous
- Length
- 460 ft
- 8 main spans
- Daily traffic
- 123
- 2016 count
- Owner
- Federal
- Corps of Engineers (Civil)
About this bridge
Stae Highway 1806 over Oahe Dam Spillway is a steel continuous girder and floorbeam system carrying Stae Highway 1806 over Oahe Dam Spillway in Stanley County, South Dakota. It was built in 1963, so it is 62 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 123 vehicles a day, roughly 17% of them trucks, projected to reach 240 by 2040. The structure is 460 ft (140.2 m) long and 38 ft wide. If it were closed, the detour would be 123.7 mi (199 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Stae Highway 1806 over Oahe Dam Spillway built?
It was built in 1963, making it 62 years old in 2025.
What condition is Stae Highway 1806 over Oahe Dam Spillway in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2023.
How much traffic does Stae Highway 1806 over Oahe Dam Spillway carry?
About 123 vehicles per day (2016 count), of which roughly 17% are trucks.
How long is Stae Highway 1806 over Oahe Dam Spillway?
The structure is 460 ft (140.2 m) long with a longest span of 58 ft (17.7 m) and a deck 38 ft wide.
Who owns Stae Highway 1806 over Oahe Dam Spillway?
It is owned by the Corps of Engineers (Civil).