Rancho Huasna was a 22,153-acre (89.65 km2) Mexican land grant in present-day San Luis Obispo County, California given in 1843 by Governor Manuel Micheltorena to Isaac J.
[1] The grant extended along the Huasna River and the western slope of the Santa Lucia Range, east of present-day Arroyo Grande and encompassing Huasna.
He arrived in Los Angeles in 1832, and by 1848 had established a large otter trapping and merchant business in Santa Barbara.
He never lived at Rancho Huasna, preferring instead to be closer to his business holdings in Santa Barbara.
[8] 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.