There are 20 US Post Offices in Beaver County serving a total of 190,687 residents equating to 9,534 residents per post office. It's estimated that approximately 304,358 packages are handled across the 20 county post offices annually. Beaver County is a county located in the U.S. state of Pennsylvania. As of the 2010 census, the population was 170,539. Its county seat is Beaver. The county was created on March 12, 1800, from parts of Allegheny and Washington Counties. It took its name from the Beaver River. Beaver County is part of the Pittsburgh, PA Metropolitan Statistical Area."