There are 11 US Post Offices in Delta County serving a total of 38,602 residents equating to 3,509 residents per post office. It's estimated that approximately 61,613 packages are handled across the 11 county post offices annually. Delta County is a county in the Upper peninsula in the U.S. state of Michigan. As of the 2010 census, the population was 37,069. The county seat is Escanaba. The county was surveyed in 1843 and organized in 1861. Its name originates from the Greek letter \"delta\", which refers to the triangular shape of the original county which included segments of Menominee, Dickinson, Iron, and Marquette counties. Delta County comprises the Escanaba, MI Micropolitan Statistical Area."