A complex and contested concept, sustainability presents a great challenge to teachers and learners. Field study is a potentially promising venue to unpack the problematics of sustainability in practice. This paper reflects on the Cascadia Sustainability Field School, offered through the University of Victoria, Canada, providing an overview of the critical pragmatic philosophy underscoring it, drawing on student voices to highlight its transformative potential and detailing our approach for assessing learning. We conclude that field school can provide a rich transformative and social learning experience that integrates the hatchet of critical reflection and the seed of practical action.