Investigations associated with the Avenue of Saints highway project resulted in the documentation of a series of Late Woodland South Branch phase (cal A.D. 600–850) occupations in the Mississippi floodplain of northeastern Missouri. These settlements represent the first South Branch sites excavated in Missouri and provided an opportunity to update what is known about the phase. This article summarizes the artifact, feature, and subsistence data recovered. As a result of this work, it is proposed that the original South Branch phase (cal A.D. 400–600) be extended and divided into two phases: South Branch I (cal A.D. 400–600) and South Branch II (cal A.D. 600–850). Reinterpretations of some large South Branch bluff-base settlements as periodically occupied focal points on the landscape are offered.