There are 24 US Post Offices in Susquehanna County serving a total of 45,096 residents equating to 1,879 residents per post office. It's estimated that approximately 71,978 packages are handled across the 24 county post offices annually. Susquehanna County is a county located in the U.S. state of Pennsylvania. As of the 2010 census, the population was 43,356. Its county seat is Montrose. The county was created on February 21, 1810, from part of Luzerne County and later organized in 1812. It is named for the Susquehanna River."