Rancho Tzabaco was a 15,439-acre (62.48 km²) Mexican land grant in present day Sonoma County, California given in 1843 by Governor Manuel Micheltorena to José German Piña (often misspelled as "Pena" in historical documents). The grant extended along Dry Creek, a tributary of the Russian River, north west of present day Healdsburg and encompassed present day Geyserville and the Dry Creek Valley AVA. The grant was immediately north of Henry D.