Certain Lower Mississippi Valley (LMV) traits, mostly Coles Creek ceramic traits, but also traits such as temple mounds and certain mortuary patterns, appear at Late Fourche Maline and Early Caddo sites in the Trans-Mississippi South, particularly at sites in the Red River Valley in northwest Louisiana and southwest Arkansas. Explaining how these traits got there and understanding their role in the development of Caddo culture is one of the basic problems in the archaeology of this area. The conventional explanation has long been that they represent a full scale intrusion of Coles Creek culture into the Trans-Mississippi South. Thus Michael Hoffman has created a Crenshaw phase of Coles Creek culture in the Great Bend region of the Red River Valley in southwest Arkansas, and Clarence H. Webb attributed the initial major occupation at the Mounds Plantation site in northwest Louisiana to Coles Creek peoples who laid out the plaza, possibly constructed Mound 2 as a quadrilateral temple substructure, and--at the opposite end of the plaza--established a burial area where Mound 5 sits
