The goal of this project was to compare the conceptual sustainability knowledge of students at two institutions that differ in their approaches of integrating sustainability into curricula. One institution is a research-intensive university that has implemented a sustainability-focused course (vertical integration), and the second is a teaching-focused university that has woven sustainability into a variety of classes across its curriculum (horizontal integration). At both institutions, students beginning their capstone design experience created concept maps (cmaps) on the focus question: "What is sustainability?" Structure of student knowledge was analyzed using the traditional cmap scoring method, while specific content was evaluated using word clouds. Results support that students engaging in the curriculum with horizontal integration demonstrated broader, deeper, and more connected knowledge than students enrolled in the vertically-integrated curriculum. Furthermore, students participating in the horizontallyintegrated curriculum demonstrated a more balanced understanding of sustainability, with the oftenneglected social dimension being significantly represented in their cmaps, as compared to students from the vertically-integrated curriculum. Economic sustainability was a common weakness.