There are 11 US Post Offices in Jasper County serving a total of 35,604 residents equating to 3,237 residents per post office. It's estimated that approximately 56,828 packages are handled across the 11 county post offices annually. Jasper County is a county located in the US state of Iowa. As of the 2010 census, the population was 36,842. The county seat is Newton. The county was organized in 1846 and is named after Sergeant William Jasper, a Revolutionary War hero. Jasper County comprises the Newton, IA Micropolitan Statistical Area, which is part of the Des Moines-Ames-West Des Moines, IA Combined Statistical Area."