South Fork Eel River

South Fork Eel River
River
Meander in the South Fork Eel River
Country	United States
State	California
Tributaries
- left	Hollow Tree Creek, Bull Creek (California)
- right	Tenmile Creek (South Fork Eel River), Rattlesnake Creek (California), Cedar Creek (South Fork Eel River), East Branch South Fork Eel River
Source
- elevation	2,500 ft (762 m)
- coordinates	39°36′46″N 123°29′34″W / 39.61278°N 123.49278°W / 39.61278; -123.49278
Mouth	Eel River
- location	Dyerville/Founders' Grove, California
- elevation	100 ft (30 m)
- coordinates	40°21′21″N 123°55′10″W / 40.35583°N 123.91944°W / 40.35583; -123.91944Coordinates: 40°21′21″N 123°55′10″W / 40.35583°N 123.91944°W / 40.35583; -123.91944
Length	105 mi (169 km)
Basin	689 sq mi (1,785 km2)
Discharge	for USGS gage 11476500, near Miranda, CA, river mile 20
- average	1,845 cu ft/s (52.2 m3/s)
- max	199,000 cu ft/s (5,635.1 m3/s)
- min	10 cu ft/s (0.3 m3/s)
Map of the Eel River drainage basin showing the South Fork

The South Fork Eel River is the largest tributary of the Eel River in north-central California in the United States. The river flows 105 miles (169 km) north from Laytonville to Dyerville/Founders' Grove where it joins the Eel River. The South Fork drains a long and narrow portion of the Coast Range of California in parts of Mendocino and Humboldt counties. U.S. Route 101 follows the river for much of its length.

The Kai Pomo Indians, a branch of the Pomo Indians group, once lived in the upper portion of the watershed. Before industrial development in the 1800s, many native tribes relied on the river's abundant runs of salmon and steelhead. In the 1920s, a private company built the Benbow Dam, blocking fish migration to a large area of the basin.

The South Fork is designated as a National Wild and Scenic River from the confluence of Section Four Creek to the mouth.

The South Fork Eel River begins near Iron Mountain in western Mendocino County, at an elevation of 2,500 feet (760 m). Its headwaters are near that of the Ten Mile River to the south. Dropping off the high plateau where it begins, the South Fork winds north and bends southwest through a steep and narrow canyon. Longvale, California is a few miles to the east of the headwaters, while Laytonville, California is closer, only about 1-mile (1.6 km) to the north. It is not long after its headwaters that Branscomb Road drops into the South Fork Eel's canyon from the north, paralleling the river. Almost 1-mile (1.6 km) past this point, it receives its first significant tributary, Section Four Creek, on the left bank. Although it is not a large creek, only about 2.5 miles (4.0 km) long, it denotes the start of the National Wild and Scenic River section of the South Fork. The river meanders swiftly west and turns west-northwest, passing Branscomb, California. Near the city, it receives Rock Creek on the right and Redwood Creek on the left. These two stream names are a common occurrence throughout the South Fork's watershed. Afterwards, it receives its first significant tributary, Tenmile Creek, on the right bank. Tenmile Creek begins in another section of the Coast Range, separated from the South Fork Eel River by two sub-ranges. The creek begins in the easternmost of these two sub-ranges. It then flows west, cutting a water gap through the western subrange, and spills into the South Fork. The creek is about 21 miles (34 km) long, despite the name.