Longvale is an unincorporated community in Mendocino County, California. It is located on Outlet Creek adjacent to the Northwestern Pacific Railroad and U.S. Route 101 9.5 mi south-southeast of Laytonville, at an elevation of 1191 feet (363 m). A post office operated at Longvale from 1911 to 1958. The post office was located in a store on the original alignment of US 101 across from Camp Piercy, near a bridge to Andersonia. The area was primarily an "auto camp" for tourists driving through the Redwood Empire on US 101.