New Research at Monte Negro, Oaxaca

Abstract Between 1937 and 1940, a team of Mexican archaeologists led by Alfonso Caso excavated at Monte Negro, a defensible mountaintop settlement in western Oaxaca. Their foundational insights into the Late Formative period (ca. 300–100 BC) were later augmented by surveys and excavations in other valleys of western Oaxaca, which revealed the emergence of contemporaneous hilltop centers. Archaeological research at Monte Negro resumed in the early 2000s with total station mapping and intensive surface collections, followed in 2023–2024 by the first excavations outside of the monumental core. In this article, we present the first complete site map along with GIS analyses, which offer new ideas about Monte Negro’s settlement layout including possible neighborhood divisions and the social functions of ceremonial plazas. We also publish the site’s first accelerator mass spectrometry (AMS) radiocarbon dates, which confirm that Monte Negro’s relatively brief occupation was in the final centuries BC. In addition, we report the discovery of two nearby sites, including a set of walls likely dating to the Late Postclassic. With further analysis of the most recent excavations forthcoming, the findings presented here refine understanding of Monte Negro’s chronology, social organization, regional role, and enduring cultural significance.