US 89 over Rock Creek
FairPark County, Montana · 2M SE Clyde Park · Structure no. P00059012+02781
- Built
- 1984
- 41 years old
- Condition
- Fair
- inspected November 2023
- Type
- Slab
- Concrete Continuous
- Length
- 79 ft
- 3 main spans
- Daily traffic
- 1,457
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US 89 over Rock Creek is a concrete continuous slab carrying US 89 over Rock Creek in Park County, Montana. It was built in 1984, so it is 41 years old, younger than the Montana average of 47 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 1,457 vehicles a day, roughly 3% of them trucks, projected to reach 1,530 by 2043. The structure is 79 ft (24.1 m) long and 46 ft wide. If it were closed, the detour would be 72.1 mi (116 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US 89 over Rock Creek built?
It was built in 1984, making it 41 years old in 2025.
What condition is US 89 over Rock Creek 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 November 2023.
How much traffic does US 89 over Rock Creek carry?
About 1,457 vehicles per day (2023 count), of which roughly 3% are trucks.
How long is US 89 over Rock Creek?
The structure is 79 ft (24.1 m) long with a longest span of 30 ft (9.1 m) and a deck 46 ft wide.
Who owns US 89 over Rock Creek?
It is owned by the State Highway Agency.