There are 6 US Post Offices in Ottawa County serving a total of 30,531 residents equating to 5,089 residents per post office. It's estimated that approximately 48,731 packages are handled across the 6 county post offices annually. Ottawa County is a county located in the northeastern corner of the U.S. state of Oklahoma. As of the 2010 census, the population was 31,848. Its county seat is Miami. The county was named for the Ottawa Tribe of Oklahoma. It is also the location of the federally recognized Modoc Tribe of Oklahoma and the Quapaw Tribe of Indians, which is based in Quapaw. Ottawa County comprises the Miami, OK Micropolitan Statistical Area, which is included in the Joplin-Miami, MO-OK Combined Statistical Area. The county borders both Kansas and Missouri.