The site of Ounjougou, Mali, provides evidence of a variety of human activities. The geological and palaeoenvironmental sequence offers a wealth of micro and macro plant remains. All the requisite elements for setting the cultural, climatic and environmental changes into chronological perspective are gathered here. Since 1997, as part of the Paleoenvironment and Human Population of West Africa project, four seasons of field work have taken place, which confirm that investigation of the site will substuntially modify our understanding of Dogon prehistory and history, and ultimately that of the whole of West Africa.