There are 5 US Post Offices in Nowata County serving a total of 10,494 residents equating to 2,099 residents per post office. It's estimated that approximately 16,750 packages are handled across the 5 county post offices annually. Nowata County is a county located in northeastern Oklahoma. As of the 2010 census, the population was 10,536. Its county seat is Nowata. The county name is derived from a Delaware word \"no-we-ata,\" meaning \"come here\" or \"welcome.\" It is located on the Kansas border."