There are 13 US Post Offices in Venango County serving a total of 51,105 residents equating to 3,931 residents per post office. It's estimated that approximately 81,569 packages are handled across the 13 county post offices annually. Venango County is a county located in the Commonwealth of Pennsylvania. As of the 2010 census, the population was 54,984. Its county seat is Franklin. The county was created in 1800 and later organized in 1805. Venango County comprises the Oil City, PA Micropolitan Statistical Area. It is defined as part of the Pittsburgh media market.