S 556-THOMPSON R R over Big Rock Creek
GoodSanders County, Montana · 35M SW Marion · Structure no. S00556028+01001
- Built
- 2009
- 16 years old
- Condition
- Good
- inspected August 2024
- Type
- Tee Beam
- Prestressed Concrete
- Length
- 49 ft
- 1 main span
- Daily traffic
- 56
- 2023 count
- Owner
- County
- County Highway Agency
About this bridge
S 556-THOMPSON R R over Big Rock Creek is a prestressed concrete tee beam carrying S 556-THOMPSON R R over Big Rock Creek in Sanders County, Montana. It was built in 2009, so it is 16 years old, younger 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 56 vehicles a day, projected to reach 59 by 2043. The structure is 49 ft (15 m) long and 19 ft wide. If it were closed, the detour would be 123.7 mi (199 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. |
| Channel and channel protection | 9 Excellent | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was S 556-THOMPSON R R over Big Rock Creek built?
It was built in 2009, making it 16 years old in 2025.
What condition is S 556-THOMPSON R R over Big Rock Creek 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 August 2024.
How much traffic does S 556-THOMPSON R R over Big Rock Creek carry?
About 56 vehicles per day (2023 count).
How long is S 556-THOMPSON R R over Big Rock Creek?
The structure is 49 ft (15 m) long with a longest span of 49 ft (15 m) and a deck 19 ft wide.
Who owns S 556-THOMPSON R R over Big Rock Creek?
It is owned by the County Highway Agency.