River, northern California, U.S. Rising near Mount Shasta , it flows 382 mi (615 km) southwest between the Cascade and Sierra Nevada ranges, through the northern Central Valley .
It forms a common delta with the San Joaquin River before entering the northern arm of San Francisco Bay . California's largest river, it is navigable for 180 mi (290 km) and accommodates oceangoing vessels as far as Sacramento . Scene of the gold rush of 1849, the river flows through one of the world's richest agricultural regions.