An intermontane valley at approximately 4,850 feet (1,480 m) elevation, Sierra Valley is surrounded by mountains ranging in elevation from 6,000 to 8,000 feet (2,400 m). The huge valley covering about 590 square miles (1,500 km2)[1] is a down-faulted basin, formerly a lake of similar geologic origin to Lake Tahoe to the south, now filled with sediment up to two thousand feet thick. The former Lake has the suggested name of Lake Beckwourth and existed until approximately 10,000 years ago.[2] Average annual rainfall is less than twenty inches, most falling as snow. The valley floor has a grassland and sagebrush ecosystem and is the site of extensive freshwater marshes filled with cattails, bulrushes and alkaline flats that drain into the Middle Fork Feather River.[3] Many species of wildlife make their permanent home in the valley, and a great number of migratory bird species stop over in the fall and nest in the valley in the spring. The valley also has thermal activity, with Marble Hot Springs located in the north central valley floor.
Economy
Sierra Valley is an agricultural and livestock region. Tourism also contributes to the local economy.
A Biological Baseline Study of Sierra Valley Marsh, California 1976. Dept. of Biology, SFSU. NSF SOS grant SMI-76-08071.
This was a student originated study funded by the National Science Foundation to assess biological resources of the high-altitude freshwater marsh in Sierra Valley. https://archive.org/details/SierraValleyStudy/page/n23
