Ashepoo River is a short blackwater river in South Carolina. It rises in a confluence of swamps south of Walterboro, flows in southeast direction and then empties into Saint Helena Sound at (32.49°N 80.42389°W). The entire course of the river lies within the boundaries of Colleton County. The Ashepoo basin forms part of the ACE Basin, a coastal conservation area that encompasses its bottomlands confluence with the Combahee and Edisto river basins (thus, the origin of the refuge's name, formed from the first letters of the names of the 3 rivers: A-C-E).