Russian River (California)
 For other uses see Russian River.The Russian River a southward-flowing river drains 1485 square miles (3846 km2) of Sonoma and Mendocino counties in Northern California. With an annual average discharge of approximately 1600000 acre feet (2.0 km3) it is the second largest river (after the Sacramento River) flowing through the nine county Greater San Francisco Bay Area with a mainstem 110 miles (177 km.) long.