The Chattahoochee Formation is an (Lower Miocene) see time scale, predominantly fine-grained, often fossiliferous, silty to sandy dolostone and limestone. Fossils include mollusks and foraminifera. The Chattahoochee Formation occurs in a limited area of the central panhandle from Walton County westward into Leon County. A classic exposure occurs along the entrance road to the Jim Woodruff Dam in Chattahoochee, Gadsden County.