The Salton Sea is an inland saline lake, located in the Sonoran Desert in Southern California north of the Imperial Valley. It is 35 miles long in its long axis, and 15 miles wide in its short axis. The sea falls within the territory of both Riverside County and Imperial County. This body of water was created in the early 20th century by accidental flooding from the Colorado River. It is now a major resource for migrating and wading birds.