As little is currently known about grassroots sentiments regarding cartography and territorial borders, especially within borderland areas, this interdisciplinary project seeks to measure popular preferences over the drawing of interstate borders. The project thus asks what territorial geographies individual citizens prefer, and whether their preferences coincide with the structural causes prevalent in previous research. To answer this question, the project develops and uses a new type of pre-registered survey experiment utilizing maps containing ethnic, historical, geographical, political, and economic features to survey approximately 1200 borderland residents. The analysis is centred on Ukraine’s westernmost region of Zakarpattia, given the region’s multi-faceted history and position neighbouring four EU states, to untangle the effects of ethnic, geographical, and historical borders on contemporary border preferences, as well as alternative explanations for individual preferences. By asking citizens living in borderland areas to draw their preferred territorial setup of states, the project grants agency to a historical understudied population, and combines geographical and sociological insight, to push forward the existing literature on state-construction and nation-building. The project’s empirical findings into the determinants of border preferences by the people who engage with borders most directly in their everyday lives-those in the borderlands-also intrinsically highlight the role and importance of grassroots border preferences for both the study and practice of global politics.