There are 6 US Post Offices in Haskell County serving a total of 13,584 residents equating to 2,264 residents per post office. It's estimated that approximately 21,682 packages are handled across the 6 county post offices annually. Haskell County is a county located in the southeast quadrant of the U.S. state of Oklahoma. As of the 2010 census, the population was 12,769. Its county seat is Stigler. The county is named in honor of Charles N. Haskell, who was the first governor of Oklahoma.