Charles Krug is the oldest commercial winery in Napa, opening in 1861. Beringer Vineyards, est. 1876, is the oldest continuously operating winery. It's Beringer's 150th anniversary.
The oldest commercial wineries in Sonoma County are in the town of Sonoma. Buena Vista opened in 1857, and Gundlach Bundschu in 1858. Buena Vista is the oldest commercial winery in the state, but it has not been continuous. Wente Vineyards, founded 1883 in Livermore, is the longest continuously operating family winery.