Historical research on interpretation poses the problem of the absence of direct sources for the reconstruction of situations in which interpreters have intervened. However, in the process of tracking the presence of institutionalized interpreters in Hispanic-American colonial sources, we find indices and references in the documents that help us in these reconstructions. Through an interdisciplinary approach (historical anthropology and interpretation studies) to chronicles and archival material related to the Hispano-mapuche treaties in the Araucanian frontier in Southern Chile (in particular during 17th-18th C.) we propose two methodological tools for approaching interpretation as a historical practice. This experience leads us to conclude that there is knowledge to be derived from past practice through interdisciplinary dialogue. From the point of view of interpretation studies, this approach takes us to depths of interpretation practice not often explored; from the perspective of historical anthropology, linguistic mediation is better clarified as an object of study.