The fight over the tar sands in North America is among the epic environmental and social justice battles of our time, and one of the first that has managed to marry quite explicitly concern for frontline communities and immediate local hazards with fear for the future of the entire planet. Tar sands “development” comes with an enormous environmental and human cost. But tar sands opponents—fighting a powerful international industry—are likened to terrorists; government environmental scientists are muzzled; and public hearings are concealed and rushed. Yet, despite the formidable political and economic power behind the tar sands, many opponents are actively building international networks of resistance, challenging pipeline plans while resisting threats to Indigenous sovereignty and democratic participation.