There are 19 US Post Offices in Lycoming County serving a total of 162,201 residents equating to 8,537 residents per post office. It's estimated that approximately 258,891 packages are handled across the 19 county post offices annually. Lycoming County is a county located in the Commonwealth of Pennsylvania. As of the 2010 census, the population was 116,111. Its county seat is Williamsport. Lycoming County comprises the Williamsport, PA Metropolitan Statistical Area. Located about 130 miles (209 km) northwest of Philadelphia and 165 miles (266 km) east-northeast of Pittsburgh, Lycoming County is the largest county in Pennsylvania in area."