This research report examines the “vertical integration” of the United Nations (UN) peace building efforts in Sierra Leone by examining the extent to which the mission reached beyond national government institutions and elites to engage society more broadly in peace building. It focuses on the country’s youth crisis as a persistent cause of conflict that presents ample opportunity for civil society engagement, and identifies two modes of coordinating youth peace building efforts across international, national and local scales. After exploring different understandings of peace building between these actors, this report ultimately argues that the United Nations fostered only weak vertical integration on the crucial issue of youth marginalization; that the lack of engagement leaves the peace vulnerable; and that deeper vertical integration can help ameliorate this ongoing challenge.