Plumas County is located near the northeast corner of California, up where the Sierra and the Cascade mountains meet. The Feather River, with its several forks, flows through the county. Quincy, the unincorporated county seat, is about 80 miles northeast from Oroville, California, and about 85 miles from Lake Tahoe and Reno, Nevada. State highways 70 and 89 traverses the county.