There are 60 US Post Offices in Erie County serving a total of 743,399 residents equating to 12,390 residents per post office. It's estimated that approximately 1,186,548 packages are handled across the 60 county post offices annually. Erie County is a county in the U.S. state of New York. As of the 2010 census, the population was 919,040. The county seat is Buffalo. The county's name comes from Lake Erie, which in turn comes from the Erie tribe of Native Americans who lived south and east of the lake before 1654. To the north of the Canada\u2013US border is the province of Ontario. Erie County is part of the Buffalo\u2013Niagara Falls metropolitan area. The county's southern part is known as the Southtowns."