There are 10 US Post Offices in Muscatine County serving a total of 45,497 residents equating to 4,550 residents per post office. It's estimated that approximately 72,618 packages are handled across the 10 county post offices annually. Muscatine County is a county located in the U.S. state of Iowa. As of the 2010 census, the population was 42,745. The county seat is Muscatine. The southeastern border is formed by the Mississippi River. Muscatine County comprises the Muscatine, IA Micropolitan Statistical Area, which is included in the Davenport-Moline, IA-IL Combined Statistical Area."