This study explores intercultural interactions in different localities of Ilocos Sur and Ilocos Norte as our contribution to the now flourishing field of local historiography. It mines the Historical Data Papers (HDP) and undertakes mapping of the data culled through the Geographical Information System (GIS), a combination of sourcing and methods which, we believe, constitutes a different approach to local histories. Because it was created mainly as a convenient database, the HDP is seldom utilized by researchers, in large part owing to questions raised concerning its data gathering methods. But with easily accessible data covering wide geographical spaces, we found the HDP ideal for our own attempt at local historiography and mapping. Maps are significant tools for the presentation and analysis of data but are also still little-used for historical analysis. With the available technology and an interdisciplinary approach, however, mapping can truly enhance local history and intercultural studies. We focused on settlement and migration patterns and, with the latter in the picture, we were able to create additional maps portraying possible movements of the people around the said provinces. The resulting six maps portray migration as a constant part of the settlement of Ilocos Sur and Ilocos Norte. From the HDP findings, the most observable migratory movements were those of Ilocanos and Cordillerans (including the Tingguians and Itnegs). The migration maps themselves provide us with ample clues on the intercultural interactions between the Ilocanos and Cordillerans and to reimagine each community’s sense of locality based on their perspectives and experiences rather than administrative or geopolitical demarcations.

Keywords: Geographical Information System (GIS), Historical Data Collection, Migration, Settlement, Ilocos Region