Los Llanos, the southern region of La Rioja Province (Argentina), has remained largely under-researched from a historical perspective, particularly regarding its earliest, early colonial, and pre-Columbian processes. This is partly due to, and in turn reinforced by, the limited nature of documentary sources and archaeological evidence. Despite this, different hypotheses have been proposed regarding its Indigenous communities: 1) the idea of a “void” region, a desert traversed by groups settled outside the area; 2) a peripheral space within the dispersion of the “Diaguita” peoples; 3) an autonomous area inhabited by a distinct ethnic group (“Olongastas”); and 4) a multicultural area resulting from the convergence of groups of different origins. This study evaluates these perspectives through the analysis of a substantial corpus of historical and toponymic information, most of it published in scattered sources, but also including previously unpublished material. The comparative approach considers analogous information published on neighboring regions. In addition to issues related to ethnic identities, linguistic systems, and extra-regional relations, this study seeks to outline the main social, political, and economic characteristics of the local pueblos de indios during the late sixteenth and early seventeenth centuries.
