S 21 over RR
GoodPondera County, Montana · Conrad · Structure no. P00021005+00501
- Built
- 1972
- 53 years old
- Condition
- Good
- inspected February 2025
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 223 ft
- 3 main spans
- Daily traffic
- 1,725
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
S 21 over RR is a prestressed concrete stringer/multi-beam or girder carrying S 21 over RR in Pondera County, Montana. It was built in 1972, so it is 53 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 1,725 vehicles a day, roughly 2% of them trucks, projected to reach 1,811 by 2043. The structure is 223 ft (67.9 m) long and 51 ft wide. If it were closed, the detour would be 9.9 mi (16 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was S 21 over RR built?
It was built in 1972, making it 53 years old in 2025.
What condition is S 21 over RR in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in February 2025.
How much traffic does S 21 over RR carry?
About 1,725 vehicles per day (2023 count), of which roughly 2% are trucks.
How long is S 21 over RR?
The structure is 223 ft (67.9 m) long with a longest span of 77 ft (23.5 m) and a deck 51 ft wide.
Who owns S 21 over RR?
It is owned by the State Highway Agency.