Community service learning offers students the opportunity to cross socially constructed and epistemological borders of power and privilege, allowing them to come into contact with groups of people who are different from themselves and to learn in different ways. Peer facilitators, undergraduate student instructional leaders who guide others through these encounters, often experience especially powerful border crossing experiences, both by virtue of their service site supervision and their seminar leadership roles. Using their own writings and interviews, we explore some of these peer facilitators' border crossing experiences in a community service learning course at a large midwestern research university. We focus on how peer facilitators encounter various issues as they guide discussion of the experiences students have at community service sites in reflective seminars. The findings suggest that such border crossing experiences can encourage peer facilitators to reflect on their own social group identity and position within the larger social structures of privilege and oppression, and on their own learning styles and engagement in the higher educational environment.