Big River (California)
| Big River Arroyo Grande | |
|---|---|
Big River, from the Big River Unit of Mendocino Headlands State Park | |
Location of the mouth in California | |
| Location | |
| Country | United States |
| State | California |
| Region | Mendocino County |
| Physical characteristics | |
| Source | Impassable Rocks |
| • location | 7 mi (11 km) south of Willits, California |
| • coordinates | 39°19′3″N 123°22′23″W / 39.31750°N 123.37306°W |
| Mouth | Pacific Ocean |
• location | Mendocino, California |
• coordinates | 39°18′8″N 123°47′41″W / 39.30222°N 123.79472°W |
• elevation | 0 ft (0 m) |
| Basin size | 181 sq mi (470 km2) |
The Big River is a 41.7-mile-long (67.1 km) river in Mendocino County, California, that flows from the northern California Coast Range to the Pacific Ocean at Mendocino, Mendocino County, California. From the mouth, brackish waters extend 8 miles (13 km) upstream, forming the longest undeveloped estuary in the state.