For the wine region, see Napa Valley AVA. 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.
Area code 412 is a Pennsylvania area code that covers Pittsburgh and some of the surrounding areas. Area code 412 overlays the area code of 878. Pennsylvania has area codes of 215, 267, 272, 412, 484, 570, 610, 717, 724, 814, 878.
Area code 256 is an area code that covers Northern Alabama. Area code 256 overlays the area code of 938. Alabama has area codes of 205, 251, 256, 334, 659, 938.rea code 256 is an area code that covers Northern Alabama. Area code 256 overlays the area code of 938. Alabama has area codes of 205, 251, 256, 334, 659, 938.