Rancho Tepusquet was a 8,901-acre (36.02 km2) Mexican land grant in present-day northern Santa Barbara County, California given in 1837 by Governor Juan B. Alvarado to Tomás Olivera.
By her previous marriage, María Antonia Cota had daughters: María Martina Osuna (who married Juan Pacifico Ontiveros of Rancho San Juan Cajón de Santa Ana in 1825)[4] and Eduarda Osuna (who married Benjamin Foxen of Rancho Tinaquaic in 1831).
With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored.
[7] In 1855, the heirs of Tomás Olivera sold Rancho Tepusquet to step daughter, María Martina Osuna (1809–1898) and son-in-law Juan Pacifico Ontiveros (1795–1877).
Juan Pacifico Ontiveros moved to Rancho Tepusquet in 1856, and constructed an adobe on the property, where he lived until his death.