Rancho San Lorenzo was a 26722 acres (108.1 km²) Mexican land grant

Ranchos of California

The Spanish, and later the Méxican government encouraged settlement of territory now known as California by the establishment of large land grants called ranchos, from which the English ranch is derived. Devoted to raising cattle and sheep, the owners of the ranchos attempted to pattern themselves...

 given in 1841 by Governor Juan Alvarado to Guillermo Castro

Guillermo Castro

Guillermo Castro was the son of Carlos Castro of Rancho San Francisco de las Llagas, near Coyote, California in Santa Clara County. He was a soldier, rancher, surveyor, and magistrate in his lifetime.-Biography:...

 a career soldier posted to the Pueblo of San José. The land grant included present day Hayward

Hayward, California

Hayward is a city located in the East Bay in Alameda County, California. With a population of 144,186, Hayward is the sixth largest city in the San Francisco Bay Area and the third largest in Alameda County. Hayward was ranked as the 37th most populous municipality in California. It is included in...

, San Lorenzo

San Lorenzo, California

San Lorenzo , also known as San Lorenzo Village is a census-designated place in Alameda County, California, United States. The population was 23,452 at the 2010 census.-Geography:...

, and Castro Valley

Castro Valley, California

Castro Valley is a census-designated place in Alameda County, California, United States. As of the 2000 census, it is the fifth most populous unincorporated area in California, and the twenty-third in the United States...

, including Crow Canyon, Cull Canyon, and Palomares Canyons.

History

Castro's grant was patented in 1865. Soon after, Castro began to sell off his land to pay debts. The last of his holding was sold in a sheriff's sale in 1864 to Faxon Atherton

Faxon Atherton

Faxon Dean Atherton was an American businessman and landowner, and was a prominent citizen of San Mateo County, California. He is the namesake of Atherton, California.-Early life:...

. Atherton in turn began selling off his portion in smaller parcels.

Rancho San Lorenzo (Sota)

Guillermo and Maria Louisa Peralta Castro owned Rancho San Lorenzo Alta. Francisco and Barbara Soto owned an adjacent rancho called Rancho San Lorenzo Baja - sometimes called San Lorenzito,or Little San Lorenzo. Barbara Soto was Guillermo Castro's sister.Soto's grant was patented at 6686 acres (27 km²) in 1877.