There are 17 US Post Offices in Ogle County serving a total of 51,925 residents equating to 3,054 residents per post office. It's estimated that approximately 82,878 packages are handled across the 17 county post offices annually. Ogle County is a county located in the U.S. state of Illinois. According to the 2010 census, it had a population of 53,497. Its county seat is Oregon, and its largest city is Rochelle. Ogle County comprises Rochelle, IL Micropolitan Statistical Area, which is also included in the Rockford-Freeport-Rochelle, IL Combined Statistical Area."