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.
When the first area code plan was introduced in 1947, the entire state was given the area code 305. In 1953, the area code 813 was introduced for the western coast of Florida, and 904 was introduced for northern Florida in 1965. In 1988, area code 407 was introduced for the Orlando area.