Feather River - Drainage Basin

Drainage Basin

The United States Forest Service manages over 80% of the Feather River's upper watershed, in the mountains above Lake Oroville. The alluvial valleys in this area are mostly privately owned and used for livestock grazing and hay production. In terms of drainage area, the North Fork Feather River is the largest, accounting for about 60% of the total basin above Lake Oroville. The Middle Fork drains about 32% of the upper basin. Other forks and tributaries drain much smaller areas—the West Fork accounts for about 5%, and the South Fork about 3%.

There are several important valleys in the otherwise mountainous upper basin. The Sierra Valley, about 470 square miles (1,200 km2), is located where a number of tributaries come together to form the Middle Fork. The valley's elevation is nearly 5,000 feet (1,500 m). It is known as the largest high-alpine valley in the continental United States. It also lies along the Pacific Flyway, making it an important seasonal home to migrating birds. Settlements in the valley include Portola, Loyalton, Sierraville, and Beckwourth.

The American Valley is located in the middle of the upper Feather basin. Spanish Creek and Greenhorn Creek join in the valley, and Spanish Creek flows north to join Indian Creek, forming the East Branch North Fork Feather River. American Valley is about 3,410 feet (1,040 m) in elevation and supports a population of about 6,500. The largest community is Quincy. Historically, American Valley was a floodplain, but settlers drained the wet meadows to create pasture for cattle and fields for hay production. Today the stream channels are deeply incised and floods rare. These alternations affected the valley's ecology. Beavers, which were once prevalent, were nearly eliminated. This in turn had a large effect on the valley's hydrology.

Indian Valley is the third important alluvial valley of the upper basin. It is located along lower Indian Creek, near its confluence with Lights Creek. By the end of the 19th century Indian Valley was considered the most important valley of Plumas County and its swampy land was developed into a prosperous agricultural landscape. Communities in Indian Valley include Greenville and Taylorsville.

Two large endorheic lakes, Eagle Lake and Honey Lake, lie north of the upper Feather River basin, across the Diamond Mountains.