There are 4 US Post Offices in Ransom County serving a total of 5,214 residents equating to 1,304 residents per post office. It's estimated that approximately 8,322 packages are handled across the 4 county post offices annually. Ransom County is a county located in the U.S. state of North Dakota. As of the 2010 census, the population was 5,457. Its county seat is Lisbon. The county was created in 1873 and organized in 1881."