Approximately 284 sq mi / 181,503 acres.
Limestone and Madison Counties AL; Giles and Lincoln Counties TN.
Alabama Cave Crayfish, White Spring Cave Crayfish.
Spring Pygmy Sunfish, Slackwater Darter, Tuscumbia Darter, Chucky Madtom.
Tennessee Pigtoe, Pale Lilliput, Painted Creekshell (H)
, Spike (H)
, Finerayed Pigtoe (H)
, Longsolid (H)
, Tennessee Clubshell (H)
, Slabside Pearlymussel (H)
Reptiles and Amphibians:
Tennessee Cave Salamander.
Anthony's Riversnail, Slender Campeloma, Armored Marstonia, Moss Pyrg, Skirted Hornsnail.
(H) = Historic (species historically occurred in the SHU or SRRU but, it has either not been collected in a number of years, and may be considered extirpated, or the species could be present but there aren’t recent records to document its presence).