(Bloomberg) - Wildfires tore through northern California’s iconic wine-growing regions of Napa and Sonoma, damaging some of the most valuable vineyards and wineries in the U.S. and leaving vintners dumbfounded.

While California’s coast accounts for a relatively small percentage of U.S. production, it is the most valuable region in the country, said Stephen Rannekleiv, a beverage analyst at Rabobank International. The lion’s share of grapes in the state are grown in the San Joaquin Valley, where cabernet sauvignon grapes go for about $400 a ton. By contrast, the same fruit from Napa Valley usually costs closer to $7,000 a ton, and can sell for as much as $50,000. High-end wines are driving demand growth in the U.S., with bottles priced over $10 seeing the biggest gains, Rannekleiv said.