There are 53 US Post Offices in Barnstable County serving a total of 229,429 residents equating to 4,329 residents per post office. It's estimated that approximately 366,194 packages are handled across the 53 county post offices annually. Barnstable County is a county located in the U.S. state of Massachusetts. As of the 2010 census, the population was 215,888. Its county seat is Barnstable. The county consists of Cape Cod and associated islands (some adjacent islands are in Dukes County and Nantucket County). Barnstable County comprises the Barnstable Town, MA Metropolitan Statistical Area, which is also included in the Boston-Worcester-Providence, MA-RI-NH-CT Combined Statistical Area. Barnstable County was formed as part of the Plymouth Colony on 2 June 1685, including the towns of Falmouth, Sandwich and others lying to the east and north on Cape Cod. Plymouth Colony was merged into the Province of Massachusetts Bay in 1691."