The earliest European name for the river, Slavyanka, appears on a Russian-American Company chart dated 1817.The river takes its current name from Russian Ivan Kuskov of the Russian-American Company, who explored the river in the early 19th century and established the Fort Ross colony 10 mi (16 km) northwest of its mouth.
It is very safe at that time for swimming and boating, with a gentle current. Holway wrote of the Russian River in his paper "The Russian River: A Characteristic Stream of the California Coast Ranges".
The river is dangerous in the winter, with swift current and muddy water. Originally, the Russian River was one of several rivers draining westward from the Mayacamas Mountains through the Mendocino Plateau to the sea, a region lifted up by tectonic forces. Being at a lower elevation, the Russian River began cutting north into the drainage area of the Navarro River.
The Russian River springs from the Laughlin Range about 5 mi (8 km) east of Willits in Mendocino County.
It flows generally southward to Redwood Valley, then past Calpella, where it is bordered by U. Route 101, to join the East Fork Russian River just below Lake Mendocino. Route 101, it descends into the Alexander Valley, where it is joined by Big Sulphur Creek.
Historically it is interesting as one of two Northern California coastal rivers mentioned in the early nineteenth century by Russian explorer K. Khlebnikov as hosting sturgeon, presumably White sturgeon (Acipenser transmontanus), along with the Pajaro River. Kuskov had sent two baidarkas to the Slavianka River to catch sturgeon, and they returned today with ten fish..largest one exceeding two arshins (4.67 feet) long".
White sturgeon are the largest freshwater fish in the United States.
The mouth is about 60 mi (100 km) north of the San Francisco Bay's Golden Gate bridge.
The lower Russian River is a popular spring, summer, and fall destination for navigation and recreation.
However, in 2007, the Sonoma County Water Agency completed a comprehensive re-evaluation of historical records, coupled with a 5-year monitoring program using underwater cameras at two fish ladders just north of Forestville.
They found that Chinook always were, and still are, "a relatively abundant, widely distributed, and naturally self-sustaining population".
The Russians called it the Slavyanka River, meaning "Slav River".