120th Street over Elm River
FairPosted for loadBrown County, South Dakota · 0.4E of Westport · Structure no. 000000007114200
- Built
- 1974
- 51 years old
- Condition
- Fair
- inspected July 2024
- Type
- Tee Beam
- Prestressed Concrete
- Length
- 80 ft
- 2 main spans
- Daily traffic
- 98
- 2022 count
- Owner
- County
- County Highway Agency
About this bridge
120th Street over Elm River is a prestressed concrete tee beam carrying 120th Street over Elm River in Brown County, South Dakota. It was built in 1974, so it is 51 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. Its operating status is: posted for load restriction.
It carries about 98 vehicles a day, roughly 2% of them trucks, projected to reach 98 by 2032. The structure is 80 ft (24.4 m) long and 31 ft wide. If it were closed, the detour would be 3.7 mi (6 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 120th Street over Elm River built?
It was built in 1974, making it 51 years old in 2025.
What condition is 120th Street over Elm River 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 July 2024.
How much traffic does 120th Street over Elm River carry?
About 98 vehicles per day (2022 count), of which roughly 2% are trucks.
How long is 120th Street over Elm River?
The structure is 80 ft (24.4 m) long with a longest span of 40 ft (12.2 m) and a deck 31 ft wide.
Who owns 120th Street over Elm River?
It is owned by the County Highway Agency.