Graptemys flavimaculata is confined to the Pascagoula River system, including the Leaf, Chickasawhay, and Escatawpa rivers, in southern Mississippi. The Leaf and Chickasawhay Rivers merge to form the Pascagoula; the Escatawpa is a tributary which joins the lower Pascagoula just before its estuary (USFWS 1993). The total range comprises less than 760 km of river [Pascagoula = 130 km, Leaf = 290 km, Chickasawhay = 340 km, but not all of this area is occupied: see the 'Population' section].