Little is known about the Ornate Diamondback Terrapin (Malaclemys terrapin macrospilota) from the Big Bend region of Florida (Wakulla, Jefferson, Taylor, and Dixie counties), and only 12 museum specimens from this area are known. We surveyed for this ecologically significant coastal species from the St. Marks River south for approximately 135 km to the Suwannee River in order to identify populations, locate and assess nesting habitats, create distribution maps for the species, and offer management recommendations to improve terrapin conservation in the Big Bend region. Using modified crab pots, head counts, and land surveys, we documented 37 new site records for Ornate Diamondback Terrapins. We captured 5 live terrapins, and recorded 5 heads, 6 intact nests, 16 crawls, terrapin material from 48 individuals, and 453 depredated terrapin nests. This survey documents the importance of the Big Bend region as significant habitat for this imperiled species. Managers should evaluate proposed development projects along this coastline for potential impacts to terrapin habitat and populations. We also recommend continued surveys of potential Diamondback Terrapin habitat along the Gulf coast of Florida so that additional populations can be located. We suggest that field studies commence at the terrapin population centers/nesting sites that we identified at Big Grass Island and vicinity, islands at the mouth of the Suwannee River, and areas surrounding the mouths of both the Steinhatchee and St. Marks rivers.