There are 4 US Post Offices in Cook County serving a total of 17,312 residents equating to 4,328 residents per post office. It's estimated that approximately 27,632 packages are handled across the 4 county post offices annually. Cook County is a county located in the U.S. state of Georgia. As of the 2010 census, the population was 17,212. The county seat is Adel. The constitutional amendment to create the county was proposed July 30, 1918, and ratified November 5, 1918. It is named for former Civil War general Philip Cook of the Confederate States Army. Reed Bingham State Park is in Cook County.