River is the largest river in California
, both in water flow and in drainage size (the drainage area includes a large proportion of interior northern California as well as some of the very southern end of Oregon
.) It flows from around Mt Shasta
to the San Francisco Bay
. Along the way it enters Lake Shasta
, then passes into the Sacramento Valley
where its waters are extensively used for agriculture
. Although some 'natural' stretches do remain, much of this river is constricted between levees. Its major tributaries are the Pit
, Yuba and American River
s. It also artificially recieves water from the Trinity River
via a tunnel; this excess water is used for irrigation, or sent to Los Angeles
or the San Joaquin Valley
Many visitors to California are surprised to find such a large river here. It is several hundreds of meters wide near where it enters its delta and is navigatable by steamboats and other small vessels. The river is even more impressive when it floods; the floodwaters are channeled into a series of vast floodplains including the Yolo and Sutter Bypasses. During these times, the river can be many miles wide, and move huge amounts of water. Those few agricultural fields in the floodplain beneifit from quite fertile soil brought in by floods. Unfortunately, most of the river is prevented from flooding by levees; historically the river dumped much valuable sediment in the basins of the valley, which is why they are so fertile. However, in many areas, efforts are being made to restore the river's natural flood regime.
Plants native to the area include cottonwood, willow, ash, box elder, and valley oak. Animals found here include salmon, hawks, the rare yellow-billed cuckoo, and a vast number of other birds. Historically, huge grizzlys also roamed the river's vast floodplains, but these are now extinct in the area.