| East Branch South Fork Eel River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | California |
| Subdivision Type4: | District |
| Subdivision Name4: | Mendocino County |
| Length: | 25miles |
| Source1: | Bell Springs Mountain |
| Source1 Coordinates: | 39.561°N -123.3711°W |
| Mouth: | South Fork Eel River |
| Mouth Coordinates: | 40.0404°N -123.4727°W |
| Basin Size: | 59sqmi |
The East Branch South Fork Eel River, a tributary of the South Fork Eel River, is formed by the confluence of Cruso Cabin Creek and Elkhorn Creek, in Mendocino County in the U.S. state of California.[1] The river is roughly 25miles long, meandering west to its confluence with the South Fork Eel at Benbow State Recreation Area. Major tributaries of the East Branch include Buck Mountain Creek, Squaw Creek, Rays Creek, and Tom Long Creek. The river flows west, turns north, and flows west again, through rugged terrain in the Coast Range of California. The East Branch is the South Fork Eel's largest tributary.