Calistoga Road over Porter Creek
Fair Condition76 years old4,400 vehicles/day
Location
| State | California |
| County | Sonoma |
| Location | 7.2 Mi Intrx With SR 12 |
| Carries | Calistoga Road |
| Crosses | Porter Creek |
| Coordinates | 38.55137, -122.65080 |
Condition Ratings
| Overall Condition | Fair |
| Channel/Waterway | 7 (Good) |
| Culvert | 5 (Fair) |
| Scour Critical | 8 — Stable, low risk |
Physical Characteristics
| Material | Concrete Continuous |
| Design | Culvert |
| Total Length | 27.9 ft (8.5 m) |
| Max Span | 13.5 ft (4.1 m) |
| Deck Area | 88.4 sq m |
| Main Spans | 2 |
| Year Built | 1950 (reconstructed 1969) |
Traffic
| Avg Daily Traffic | 4,400 (2015) |
| Truck Traffic | 5% |
| Lanes On Bridge | 2 |
Inspection & Ownership
| Last Inspection | October 2024 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | 20C0120 |