The Paleoanthropological Inventory of Ethiopia is a long-term project designed to assess the paleoanthropological resources of the Ethiopian rift system. Inventory work completed in 1989 has established several new research areas. One of these, the Kesem-Kebena area near the northern terminus of the Main Ethiopian Rift, has now been investigated by the inventory team, and several vertebrate paleontological and archaeological localities have been discovered. The deposits range from >3.7 Ma (million years of age; Pliocene) to Late Pleistocene. Important stratigraphic units were dated by conventional K/Ar dating on basaltic lavas and 40Ar/39Ar on feldspar separates from key tephra horizons. Among the most significant discoveries from the extensive Kesem-Kebena sedimentary succession are Pleistocene Acheulian lithic assemblages and Acheulian fauna dating to ca. 1.0 Ma.