There are 9 US Post Offices in Starr County serving a total of 61,163 residents equating to 6,796 residents per post office. It's estimated that approximately 97,623 packages are handled across the 9 county post offices annually. Starr County is a county located in the U.S. state of Texas. As of the 2010 census, its population was 60,968. Its county seat is Rio Grande City. The county was created in 1848. It is named for James Harper Starr, who served as Secretary of the Treasury of the Republic of Texas. Starr County comprises the Rio Grande City, TX Micropolitan Statistical Area, which is also included in the McAllen-Edinburg, TX Combined Statistical Area. It is northeast from the Mexican border."