Cerro Romauldo is a 1,300-foot (396 m) hill in San Luis Obispo County, California. The hill is the fifth in a series of volcanic plugs called the Nine Sisters. Until 1964 the hill was officially known as Romauldo Peak. The hill is named for a Chumash man who received the 117-acre (0.47 km2) Mexican land grant from Pío Pico, the last Mexican Governor of Alta California. Huerta de Romauldo means Romauldo's kitchen garden or orchard in Spanish. He sold the land to Captain John Wilson in 1846. In the 1890s, rock from Cerro Romauldo was used in the construction of the Southern Pacific Railroad.