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.
410 Area Code 410. At AreaCode.org, you'll find helpful information on the 410 area code, including 410 area code location. Other phone area codes may be found using AreaCode.org's area code locator. Use the search function for area code look up. Click for your international toll free numbers right now.10 Area Code 410. At AreaCode.org, you'll find helpful information on the 410 area code, including 410 area code location. Other phone area codes may be found using AreaCode.org's area code locator. Use the search function for area code look up. Click for your international toll free numbers right now.