Don Raymundo Olivas and his friend Felipe Lorenzana were granted 4,670 acres of land by Mexican Governor Juan B. Alvarado as compensation for their service to the State. Don Raymundo began ranching his land, known as Rancho San Miguel, in 1847.
In 1848, gold was discovered in the American River and California history changed forever with the “Gold Rush”. Individuals, referred to as minors, came from all over the world to mine for gold. Knowing the miners needed food, Don Raymundo's cattle herd became his gold mine. These were prosperous times for Don Raymundo. With his new income, Don Raymundo finished the second story of his home. His home, which remains today, was one of the few two-story haciendas in Southern California and one of the most impressive homes in the Santa Clara River Valley. For many years Rancho San Miguel prospered, and Don Raymundo became known for his elaborate parties.
In the 1860’s, droughts in California destroyed most cattle empires. Don Raymundo was able to save his empire by raising sheep instead of cattle.
In 1864, Don Raymundo’s business partner Felipe Lorenzana sold his half of Rancho San Miguel.
The death of Don Raymundo in 1879 was the beginning of the end for the Olivas' fortune. Though some family members retained pieces of the land grant until as late as 1968, the house was sold in 1899. Rebecca Olivas, youngest daughter of Don Raymundo, was the last member of the Olivas family to live at the adobe.
After passing through many hands, the Rancho San Miguel land grant, known today as the Olivas Adobe, was purchased by yeast king Max Fleischmann who restored the adobe building in 1927. Upon Fleischmann's death, the adobe was given to the City of Ventura.
In 1972, the Olivas Adobe opened to the public as a museum.
In 1979, the Olivas Adobe was placed on the National Register of Historical Places.