Gillespie Slideroc over Clark Fork
FairMissoula County, Montana · Gillespie-Sliderock · Structure no. 011603000000076
- Built
- 1965
- 60 years old
- Condition
- Fair
- inspected July 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 213 ft
- 3 main spans
- Daily traffic
- 50
- Owner
- Federal
- U.S. Forest Service
About this bridge
Gillespie Slideroc over Clark Fork is a prestressed concrete stringer/multi-beam or girder carrying Gillespie Slideroc over Clark Fork in Missoula County, Montana. It was built in 1965, so it is 60 years old, older 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 6 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 213 ft (64.9 m) long and 29 ft wide. If it were closed, the detour would be 98.2 mi (158 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 | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Gillespie Slideroc over Clark Fork built?
It was built in 1965, making it 60 years old in 2025.
What condition is Gillespie Slideroc over Clark Fork 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 2023.
How much traffic does Gillespie Slideroc over Clark Fork carry?
About 50 vehicles per day (latest count).
How long is Gillespie Slideroc over Clark Fork?
The structure is 213 ft (64.9 m) long with a longest span of 72 ft (21.8 m) and a deck 29 ft wide.
Who owns Gillespie Slideroc over Clark Fork?
It is owned by the U.S. Forest Service.