There are 4 US Post Offices in Cimarron County serving a total of 2,387 residents equating to 597 residents per post office. It's estimated that approximately 3,810 packages are handled across the 4 county post offices annually. Cimarron County is the westernmost county in the U.S. state of Oklahoma. As of the 2010 census, the population was 2,475, making it the least-populous county in Oklahoma. Its county seat is Boise City. Located in the Oklahoma Panhandle, Cimarron County contains the only community in the state (Kenton) that observes the Mountain Time Zone. Black Rock Mesa, the highest point in the state, is in the northwest corner of the county. Throughout most of its history it has had both the smallest population and the lowest population density of any county in Oklahoma."