There are 3 US Post Offices in Garden County serving a total of 2,245 residents equating to 748 residents per post office. It's estimated that approximately 3,583 packages are handled across the 3 county post offices annually. Garden County is a county in the U.S. state of Nebraska. As of the 2010 census, the population was 2,057. Its county seat is Oshkosh. In the Nebraska license plate system, Garden County is represented by the prefix 77 (it had the seventy-seventh-largest number of vehicles registered in the state when the license plate system was established in 1922)."