Cerro Romualdo is a mountain in

San Luis Obispo County, California San Luis Obispo County (), officially the County of San Luis Obispo, is a County (United States), county on the Central Coast of California. As of the 2020 United States census, the population was 282,424. The county seat is San Luis Obispo ...

. The mountain is the fifth in a series of

volcanic plug A volcanic plug, also called a volcanic neck or lava neck, is a volcano, volcanic object created when magma hardens within a Volcanic vent, vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if risi ...

s called the Nine Sisters. Until 1964 the mountain was officially known as Romualdo Peak. The mountain is named for a Chumash man who received the

Rancho Huerta de Romualdo Rancho Huerta de Romualdo was a Mexican land grant in present-day San Luis Obispo County, California given in 1842 by Governor Juan B. Alvarado and in 1846 by Governor Pío Pico to Romualdo. The name means Romualdo's vegetable garden. The gran ...

Mexican land grant from

Pío Pico Don (honorific), Don Pío de Jesús Pico IV (May 5, 1801 – September 11, 1894) was a California politician, ranchero, and entrepreneur, famous for serving as the List of governors of California before 1850, last governor of Alta California und ...

, the last Mexican Governor of

Alta California Alta California (, ), also known as Nueva California () among other names, was a province of New Spain formally established in 1804. Along with the Baja California peninsula, it had previously comprised the province of , but was made a separat ...

. ''Huerta de Romualdo'' means ''Romualdo's kitchen garden or orchard'' in

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ...

. He sold the land to Captain John Wilson in 1846. In the 1890s, rock from Cerro Romualdo was used in the construction of the

Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials) was an American Railroad classes#Class I, Class I Rail transport, railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was oper ...

. Cerro Romualdo is owned by the

State of California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, and is used by the

California National Guard The California National Guard (Cal Guard) is part of the National Guard (United States), National Guard of the United States, a dual federal–state military reserve force in the state of California. It has three components: the California Army ...

at adjacent Camp San Luis Obispo for fitness training.

References

{{Nine Sisters Nine Sisters Mountains of Southern California Volcanic plugs of California Landforms of San Luis Obispo County, California Volcanoes of California