There are 3 US Post Offices in Lake County serving a total of 2,629 residents equating to 876 residents per post office. It's estimated that approximately 4,196 packages are handled across the 3 county post offices annually. Lake County is a county located in the U.S. state of Tennessee. As of the 2010 census, the population was 7,832, making it the fifth-least populous county in Tennessee. Its county seat is Tiptonville. It is the state's northwesternmost county, sharing a border with Kentucky and separated from Missouri to the west by the Mississippi River. Reelfoot Lake occupies much of the northern part of the county."