Rancho San Juan Cajón de Santa Ana

Rancho San Juan Cajón de Santa Ana was a 35,971-acre (145.57 km2) Mexican land grant in present-day Orange County, California.

In 1825, Ontiveros married María Martina Osuna (1809–1898), step daughter of Tomás Olivera, grantee of Rancho Tepusquet.

[5] 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.

In 1855, Ontiveros bought Rancho Tepusquet, in present-day northern Santa Barbara County, from his father-in-law Tomás Olivera.

[9] In 1857, Ontiveros sold 1,160 acres (4.7 km2) that would become Anaheim, to George Hansen who was working for 50 German-American families from the San Francisco Bay Area.