There are 8 US Post Offices in Sac County serving a total of 9,945 residents equating to 1,243 residents per post office. It's estimated that approximately 15,873 packages are handled across the 8 county post offices annually. Sac County is a county located in the U.S. state of Iowa. As of the 2010 census, the population was 10,350. The county seat is Sac City. In February 2007, in its third annual list of the \u201cBest Places to Live in Rural America\u201d, Progressive Farmer magazine placed Sac County as #7 in the overall rankings. In 2009, the magazine ranked Sac County as the tenth \"Best Place\" in the Midwest Region."