major wine production shifted to the sonoma valley in northern california largely because of its excellent climate for growing grapes. general mariano vallejo, former commander of the presidio of sonoma, became the first large-scale winegrower in the valley. in 1857, agoston haraszthy bought near vallejo's vineyards. in contrast to vallejo and most others, haraszthy planted his vines on dry slopes and did not irrigate them. today, the value of dry farming to creating superior wine is generally recognized.