There are 4 US Post Offices in Morrill County serving a total of 5,222 residents equating to 1,306 residents per post office. It's estimated that approximately 8,335 packages are handled across the 4 county post offices annually. Morrill County is a county located in the U.S. state of Nebraska. As of the 2010 census, the population was 5,042. Its county seat is Bridgeport. In the Nebraska license plate system, Morrill County is represented by the prefix 64 (it had the sixty-fourth-largest number of vehicles registered in the county when the license plate system was established in 1922)."