There are 1 US Post Offices in Sterling County serving a total of 1,143 residents equating to 1,143 residents per post office. It's estimated that approximately 1,824 packages are handled across the 1 county post offices annually. Sterling County is a county located on the Edwards Plateau in the U.S. state of Texas. As of the 2010 census, its population was 1,143, making it the ninth-least populous county in Texas. Its county seat is Sterling City. The county is named for W. S. Sterling, an early settler in the area. Sterling County is one of 30 prohibition, or entirely dry, counties in the state of Texas."