Road 21N16 over Sly Creek Spillway (dam)
GoodButte County, California · No Data Entered · Structure no. 051153000001035
- Built
- 1961
- 64 years old, rebuilt 2000
- Condition
- Good
- inspected September 2024
- Type
- Stringer/Multi-beam or Girder
- Steel
- Length
- 59 ft
- 1 main span
- Daily traffic
- 50
- Owner
- Federal
- U.S. Forest Service
About this bridge
Road 21N16 over Sly Creek Spillway (dam) is a steel stringer/multi-beam or girder carrying Road 21N16 over Sly Creek Spillway (dam) in Butte County, California. It was built in 1961 and reconstructed in 2000, so it is 64 years old, older than the California average of 54.8 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 59 ft (18 m) long and 20 ft wide. If it were closed, the detour would be 620.7 mi (999 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 | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Road 21N16 over Sly Creek Spillway (dam) built?
It was built in 1961, making it 64 years old in 2025. It was reconstructed in 2000.
What condition is Road 21N16 over Sly Creek Spillway (dam) 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 September 2024.
How much traffic does Road 21N16 over Sly Creek Spillway (dam) carry?
About 50 vehicles per day (latest count).
How long is Road 21N16 over Sly Creek Spillway (dam)?
The structure is 59 ft (18 m) long with a longest span of 58 ft (17.7 m) and a deck 20 ft wide.
Who owns Road 21N16 over Sly Creek Spillway (dam)?
It is owned by the U.S. Forest Service and maintained by the Private (other than railroad).