Portola is the only incorporated city in Plumas County, California, United States. The population was 2,104 at the 2010 census, down from 2,227 at the 2000 census. Portola is located on the Middle Fork of the Feather River and was named after Spanish explorer Gaspar de Portolá, although he did not explore this area. Portola is a crew change site on the Western Pacific Railroad Feather River Route over the Sierra Nevada.