There are 9 US Post Offices in Polk County serving a total of 45,286 residents equating to 5,032 residents per post office. It's estimated that approximately 72,282 packages are handled across the 9 county post offices annually. Polk County is a county located in the U.S. state of Texas. As of the 2010 census, the population was 45,413. Its county seat is Livingston. The Alabama-Coushatta Indian Reservation of the federally recognized tribe is in Polk County, where the people have been since the early 19th century, after migrating from the Southeast. The 2000 census reported a resident population of 480 persons within the reservation. The tribe reports 1100 enrolled members."