Rancho Jurupa was a 40,569-acre (164.18 km2) Mexican land grant in California, United States, that is divided by the present-day counties of Riverside and San Bernardino. The land was granted to Juan Bandini by Governor Juan B. Alvarado in 1838. Located along both banks of the Santa Ana River in southern California, the rancho included much of the land in the present day city of Jurupa Valley, as well as the downtown area in the city of Riverside.
"Seven leagues of grazing land: a little more," is how the "then almost worthless, but now invaluable," tract known as Jurupa Ranch came into being on September 28, 1838, through a grant made from Juan B. Alvarado (then Governor of California) to Juan Bandini (1800-1859).
Riverside historians, have proposed that the original seven square league (approximately 31,000 acres (125 km2)) Rancho Jurupa land grant was significantly smaller than the area eventually recognized by the United States. They argue that Pachappa hill, the southeast marker of the Rancho Jurupa, was originally the name of another hill, today known as Mount Rubidoux, and that one of the early owners of Rancho Jurupa reassigned the name Pachappa to the current day Pachappa hill in order to expand the property of the Rancho.
In 1841 Abel Stearns (1798–1871) married Bandini's daughter Arcadia. 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. As required by the Land Act of 1851, Juan Bandini filed a claim for the major portion of the grant in 1852, and was confirmed by the US District Court in 1855. In 1857 Juan Bandini sold this portion of the grant to his son-in-law, Abel Stearns. Stearns received a US land patent for this 33,819-acre (136.86 km2) portion of the original Rancho Jurupa grant in 1879.