There are 11 US Post Offices in Napa County serving a total of 164,070 residents equating to 14,915 residents per post office. It's estimated that approximately 261,874 packages are handled across the 11 county post offices annually. Napa County is a county located north of San Pablo Bay in the northern portion of the U.S. state of California. As of the 2010 census, the population was 136,484. The county seat is the City of Napa. Napa County was one of the original counties of California, created in 1850 at the time of statehood. Parts of the county's territory were given to Lake County in 1861. Napa County comprises the Napa, CA Metropolitan Statistical Area, which is also included in the San Jose-San Francisco-Oakland, CA Combined Statistical Area. It is one of four North Bay counties. Napa County, once the producer of many different crops, is known today for its regional wine industry, rising to the first rank of wine regions with France by local wineries Stag's Leap Wine Cellars and Chateau Montelena winning the \"Judgment of Paris\" in 1976."