This conceptual article examines the role of team-building in outdoor learning, reviews group development theory in relation to teamwork, and outlines the Behaviour Analysis model as a tool to facilitate team-building. Working with this foundation, the theory and model are combined with discussion about team, leader, and facilitator behaviours at each stage of group development. The applications are valid for all clientele in all outdoor settings. Several strong recommendations for practitioner behaviours and future research are presented.