"[8] Juan Rodríguez Cabrillo and his expedition may have travelled as far north as the Russian River in November 1542 before storms forced them to turn back south towards Monterey.

According to the USGS, variant names of the Russian River include Misallaako, Rio Ruso, Shabaikai, and Slavyanka.

[2] 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.S. Route 101, to join the East Fork Russian River just below Lake Mendocino.

[16] The Russian River was prevented from flowing south into San Pablo Bay, due to a 113-foot high ridge at Cotati.

[21] The Russian River reached flood stage of 32 feet (9.8 m) at Guerneville about five times per decade through the last half of the 20th century.

[24] Khlebnikov stated in his "1820 Travel Notes", "Mr. Kuskov had sent two baidarkas to the Slavyanka River to catch sturgeon, and they returned today with ten fish...the largest one exceeding two arshins (4.67 feet) long".

[25] Moyle's Inland Fishes of California states that there were historic runs of white, but not green, sturgeon in the Russian River.

However, in 2007, the Sonoma County Water Agency completed a comprehensive re-evaluation of historical records, coupled with a five-year monitoring program using underwater cameras at two fish ladders just north of Forestville.

In 2011, biologists estimate that more than 190 adult coho may have returned to the Russian River watershed, beginning with early storms in October and peaking in December.

[29] High priority tributaries for restoration of stream flows and habitat for Coho include Dutch Bill, Grape, Green Valley, Mark West and Mill Creeks.

[30] Similarly, early twentieth-century naturalists were skeptical that California Golden beaver (Castor canadensis subauratus) were extant in the coastal streams of the Bay Area.

[31] 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.

[32] 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.

(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)[34] 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.

[35] Hudson's Bay Company's Alexander R. McLeod reported in 1829, "The Country to the northward of Bodega is said to be rich in Beaver and no encouragement given to the Indians to hunt.

"[36] The fur trapper Ewing Young, led an expedition up Putah Creek to Clear Lake and on to the Mendocino County Coast in March, 1833.