The Eel River is a major river system of the northern Pacific coast of the U.S. state of California. Approximately 200 miles (322 km) long, it drains a rugged area in the California Coast Ranges between the Sacramento Valley and the ocean. For most of its course, the river flows northwest, parallel to the coast.
The Eel River's watershed of 3,684 square miles (9,537 sq km) is the third largest in California. The river and its tributaries total 3,448 river miles (5,548 km), flowing through five counties.
The river originates on the southern flank of Bald Mountain in northeastern Mendocino County. It flows south, then west, through Mendocino National Forest and Lake County. It is impounded in Lake Pillsbury, the reservoir created by Scott Dam.
Below Lake Pillsbury the Eel River re-enters Mendocino County, turning northwest approximately 15 miles (24 km) east of Willits. It flows northwest in a long isolated valley, collecting many tributaries including the Middle Fork Eel River and the North Fork Eel River. Between these two tributaries the Round Valley Indian Reservation lies east of the Eel River.
After the North Fork confluence, the Eel River flows through the southwestern corner of Trinity County then crosses Humboldt County from the southeast to northwest, flowing in a winding course past a series of small mountain communities. The South Fork Eel River joins as the river valley widens. U.S. Route 101 runs along the South Fork Eel River and then the main Eel River's lower course.
After passing Rio Dell, the Eel River is joined by the Van Duzen River. Below that confluence, the Eel passes Fortuna and enters the Pacific in central Humboldt County, approximately 15 miles (24 km) south of Eureka.
Salmon, Steelhead, Rainbow Trout, Brown Trout, Bass, Panfish, Perch, Halibut, Cabezon, and Lingcod are just some of the fish that can be pursued here.