There are 5 US Post Offices in Pierce County serving a total of 19,569 residents equating to 3,914 residents per post office. It's estimated that approximately 31,234 packages are handled across the 5 county post offices annually. Pierce County is a county located in the U.S. state of Georgia. As of the 2010 census, the population was 18,758. The county seat is Blackshear. Pierce County is part of the Waycross, GA Micropolitan Statistical Area.