There are 8 US Post Offices in Richland County serving a total of 20,730 residents equating to 2,591 residents per post office. It's estimated that approximately 33,087 packages are handled across the 8 county post offices annually. Richland County is a county in the U.S. state of Wisconsin. As of the 2010 census, the population was 18,021. Its county seat is Richland Center. The county was created from the Wisconsin Territory in 1842 and organized in 1850. It is named for the high quality of its soil. Some rural areas in the county have their power provided by the Richland Electric Cooperative."