Existing data suggest weak human occupation of southern Africa's Winter Rainfall Zone (WRZ) during later Marine Isotope Stage (MIS) 3, the causes of which are unknown. Here we report briefly on the results of recent surveys of alluvial terrace sites of the Doring River in the WRZ, which document occupation over a broad expanse of the later Middle Stone Age (MSA) and Pleistocene Later Stone Age. We then report on test excavations at one terrace site, denoted Putslaagte site 1 (PL1), describe in detail the assemblage of flaked stone artefacts produced from that excavation, and present two OSL ages obtained from 0.8 m to 1.5 m below surface. The results suggest that a) artefact accumulations at PL1 are dense, b) the technological systems documented are characteristically MSA but differ in form from the range of systems known from other excavated sites in the region, and c) that the assemblages accumulated in MIS 3. Taken together with the survey data the results introduce new variation into the later MSA in southern Africa, and imply reorganisation of land use in the WRZ in late MIS 3 rather than abandonment. We suggest that a research emphasis on rock shelter deposits may have produced misleading depictions of regional occupation.