Lone Rock Road over Grass Valley Canyon
FairSherman County, Oregon · 2.5 MI SE of HWY 97 · Structure no. 558812003302050
- Built
- 1960
- 65 years old
- Condition
- Fair
- inspected August 2024
- Type
- Tee Beam
- Concrete Continuous
- Length
- 114 ft
- 3 main spans
- Daily traffic
- 168
- 2020 count
- Owner
- County
- County Highway Agency
About this bridge
Lone Rock Road over Grass Valley Canyon is a concrete continuous tee beam carrying Lone Rock Road over Grass Valley Canyon in Sherman County, Oregon. It was built in 1960, so it is 65 years old, older than the Oregon average of 49.9 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 168 vehicles a day, roughly 10% of them trucks, projected to reach 173 by 2025. The structure is 114 ft (34.7 m) long and 29 ft wide. If it were closed, the detour would be 9.9 mi (16 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| 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 Lone Rock Road over Grass Valley Canyon built?
It was built in 1960, making it 65 years old in 2025.
What condition is Lone Rock Road over Grass Valley Canyon 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 August 2024.
How much traffic does Lone Rock Road over Grass Valley Canyon carry?
About 168 vehicles per day (2020 count), of which roughly 10% are trucks.
How long is Lone Rock Road over Grass Valley Canyon?
The structure is 114 ft (34.7 m) long with a longest span of 44 ft (13.4 m) and a deck 29 ft wide.
Who owns Lone Rock Road over Grass Valley Canyon?
It is owned by the County Highway Agency.