Rancho San Bernardino was a 35,509-acre (143.70 km2) Mexican land grant in present-day San Bernardino County, California given in 1842 by Governor Juan B. Alvarado to José del Carmen Lugo, José María Lugo, Vicente Lugo, and Diego Sepulveda. The grant included a large part of the San Bernardino valley, and encompassed present-day San Bernardino, Fontana, Rialto, Redlands and Colton.