There are 6 US Post Offices in Beaver County serving a total of 7,544 residents equating to 1,257 residents per post office. It's estimated that approximately 12,041 packages are handled across the 6 county post offices annually. Beaver County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 5,636. The county seat is Beaver. The name was given because of the presence of many beaver dams on the Beaver River, which runs through the area. It is located in the Oklahoma Panhandle."