The Russian River is the largest river in the Central California Coast Steelhead trout (Oncorhynchus mykiss) Distinct population segment.
Natural waterfalls and the two major dams, Warm Springs (built in 1982) and Coyote (built in 1959), have isolated anadromous steelhead from its non-oceangoing rainbow trout form above the impassable barriers.
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.
This vulnerability was demonstrated in March 1982 when a tank car of formaldehyde was vandalized in Ukiah.
In one fell swoop, the Russian River took Big Sulphur Creek (formerly the upper Navarro River) and the north fork of the Navarro River, going north to Hopland and to Ukiah.
However, the Russian-American Company's Ivan Kuskov sailed into Bodega Bay in 1809 on the Kodiak and, after exploring 50 miles of the Russian River, returned to Novo Arkhangelsk, Alaska (Sitka), with beaver skins and over 2,000 sea otter (Enhydra lutris) pelts.
The Russians' stated reason for establishing a settlement in Alta California was, "The rich, fertile soil [and] the abundance of seal, otter and beaver were the principal factors which favored this colonization." An 1816 report by the Russian-American Company's Board of Directors said that it was establishing a settlement to introduce agriculture.(page 33, After December 16, 1813: A report to Emperor Alexander I from the Russian American Company Council, concerning trade with California and the establishment of Fort Ross) Before establishing a southern colony at Fort Ross, the Russian-American Company contracted with American ships beginning in 1806, providing them with Aleuts and their baidarkas (kayaks) to hunt otter on the coast of Spanish California.
Recent genetic studies on steelhead collected at 20 different sites both above and below passage barriers in the watershed found that despite the fact that 30 million hatchery trout were stocked in the river from 1911 to 1925, the steelhead remain of native and not hatchery stock.
Until recently, most reviews indicated that Chinook salmon (Oncorhynchus tshawytscha) were always scarce on the Russian River.