The South Sulphur River flows through Delta, Fannin, Hopkins, Hunt, and Lamar Counties in northeast Texas, eventually joining with the North Sulphur River to form the Sulphur River system. This tributary system features stained to turbid water clarity typical of northeast Texas waterways, with a predominantly slow-moving current through channelized and unchannelized sections. The river provides habitat for diverse warmwater fish species and flows through a mix of dense forests along the southern reaches and farmlands with tree-lined shorelines to the north. The river is bordered by the North Sulphur River to the north and forms the eastern boundary where the two waterways converge. Big Creek, a tributary of the South Sulphur River in Delta County, feeds into Big Creek Reservoir near Cooper, while the main river channel feeds into Jim Chapman Lake (also known as Cooper Lake) at the confluence of the Middle and South Forks.