There are 7 US Post Offices in Houston County serving a total of 19,952 residents equating to 2,850 residents per post office. It's estimated that approximately 31,846 packages are handled across the 7 county post offices annually. Houston County is a county located in the U.S. state of Minnesota. As of the 2010 census, the population was 19,027. Its county seat is Caledonia. Houston County is included in the La Crosse-Onalaska, WI-MN Metropolitan Statistical Area."