Postsecondary educators have long been faced with the challenge of developing the leadership capacity of their students. This research investigated the following research question: To what degree do formal opportunities for involvement predict durable growth in leadership capacity in students who participate in a formal leadership development initiative? The study sample was drawn from the population of university students who participated in a 6-day LeaderShape Institute during the 2014-2015 academic year. These institutes were partnerships between postsecondary institutions and LeaderShape, Inc., a not-for-profit leadership education organization, where students in groups of 40-70 travel off campus for 6 days with a small group of faculty and staff facilitators for the purpose of student leadership development. A total of 226 students completed the surveys to be included within the analysis. To investigate the effects of campus involvement, students reported the degree to which they were involved in the following activities on campus: formal community service or service learning initiatives, on-campus employment, collaborative learning projects as part of academic coursework, academic courses focused on leadership theory and practice, conversations with faculty or staff they consider personal mentors, student organizations, formal positions of leadership within student organizations, and supervision of peers through formal (e.g., employment) or informal (e.g., team captain) means. Results suggest that students' ability to identify a faculty or staff mentor may serve as an important pathway to broad-based sustainable leadership growth for students. Enrolling in academic courses focused on leadership development also served as a predictor of sustainable gains in thinking of oneself as a leader.