The Mapa de Otumba, a sixteenth-century document (1550–1575) currently archived in the Biblioteca Nacional de Antropología e Historia of the Museo Nacional de Antropología in Mexico, represents a small portion of the pre-Conquest altepetl of Otompan and its Early Colonial-period administrative successors, the parroquia and corregimiento of Otumba. The exact circumstances under which the map was executed, its original purpose, and any associated textual documents are unknown. The paper on which the map is executed (amate) and the style in which it was drawn clearly show pre-Conquest paper and the hand of a tlacuilo (scribe) influenced by post-Conquest style, script, and changes in sociopolitical and religious organization. Analysis of the elements of the document reveal its temporal and spatial setting; it also throws light on the changes in indigenous sociopolitical and religious organization during the first half-century of the Early Colonial period.