While conducting archaeological survey to document the large prehistoric canal systems in the central portion of the Tehuacán Valley, investigators recorded a mound and plaza complex that includes what appears to be an effigy mound in the shape of a scorpion. Large quantities of ceramics, including surface-decorated and polychromes, indicate a Late Classic and Postclassic occupation. The site is interpreted as being part of an intensive agricultural system as it appears centrally located in the context of highly developed agricultural and irrigation infrastructure. For the reasons described, we interpret this ca. 60 meter scorpion effigy mound as an intentional feature with possible astronomical alignments. It is hypothesized as being part of a local civic/ceremonial complex with the possible use/function of observing the summer and winter solstices. If so, it provides an insight into the integration of calendrical ritual with the surrounding complex system of fields and irrigation canals. Admittedly, these observations and explanations are relatively subjective. However, we consider them to be persuasive when the evidence is considered in its entirety.