There are 6 US Post Offices in Teton County serving a total of 5,990 residents equating to 998 residents per post office. It's estimated that approximately 9,561 packages are handled across the 6 county post offices annually. Teton County is a county located in the U.S. state of Montana. As of the 2010 census, the population was 6,073. Its county seat is Choteau. The county was founded in 1893."