There are 5 US Post Offices in Keith County serving a total of 8,078 residents equating to 1,616 residents per post office. It's estimated that approximately 12,893 packages are handled across the 5 county post offices annually. Keith County is a county located in the U.S. state of Nebraska. As of the 2010 census, the population was 8,368. Its county seat is Ogallala. In the Nebraska license plate system, Keith County is represented by the prefix 68 (it had the sixty-eighth-largest number of vehicles registered in the county when the license plate system was established in 1922)."