There are 12 US Post Offices in Caddo County serving a total of 27,255 residents equating to 2,271 residents per post office. It's estimated that approximately 43,502 packages are handled across the 12 county post offices annually. Caddo County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 29,600. Its county seat is Anadarko. Created in 1901 as part of Oklahoma Territory, the county is named for the Caddo tribe who were settled here on a reservation in the 1870s. Caddo County is immediately west of the seven-county Greater Oklahoma City metro area, and although is not officially in the metro area, it has many economic ties in this region.