Plumas County, California
Plumas County ( ) is a county located in the Sierra Nevada of the U.S. state of California. As of the 2020 United States census, the population was 19,790. The county seat is Quincy, and the only incorporated city is Portola. The largest community in the county is East Quincy. The county was named for the Spanish Río de las Plumas (the Feather River), which flows through it. It is also the namesake of a native moth species, Hadena plumasata.