There are 2 US Post Offices in Montour County serving a total of 18,524 residents equating to 9,262 residents per post office. It's estimated that approximately 29,566 packages are handled across the 2 county post offices annually. Montour County is a county located in the U.S. state of Pennsylvania. As of the 2010 census, the population was 18,267. Its county seat is Danville. The county is named for Andrew Montour, a prominent M\u00e9tis interpreter who served with George Washington during the French and Indian War. It encompasses 132 sq mi, making it the smallest county by land area in the state. Montour County is part of the Bloomsburg-Berwick, PA Metropolitan Statistical Area."