We are both immensely pleased to have played supporting roles in the archaeological research that led to this volume. As a faculty member at the Universidad del Centro (Huancayo) in the 1960s and later at the Universidad Nacional de San Marcos (Lima), Matos Mendieta developed a special interest in the Upper Mantaro and adjacent Tarma drainages, and during the 1960s and 1970s, he carried out general reconnaissance and several excavations in the area...