In the late 2000s, when the oil sands industry proposed expanding its capacity to transport fossil fuel products, an unprecedented coalition of Indigenous nations and communities, environmental non-governmental organizations, grassroots groups, and municipal governments mobilized in response. Mega Pipelines, Mega Resistance explores how these social movements challenged powerful corporate and government interests and reshaped the politics of energy infrastructure. Amy Janzwood investigates campaign coalitions that were formed to oppose two mega pipeline projects: the expansion of Trans Mountain, which was ultimately completed; and Northern Gateway, which was never built. Drawing on a wide array of documents and in-depth insider interviews with oil executives, senior government officials, coalition organizers, and lawyers, she analyzes the strategic alliances and tactics that have empowered – and attempted to thwart – these movements. The campaigns effectively adapted their strategies to shifting legal, political, and economic conditions, maximizing their impact and wielding influence in ways that cannot be explained by political decisions or economic factors alone. Mega Pipelines, Mega Resistance is an ambitious study that underscores the power of campaign coalitions to sustain resistance, influence government policy, and shape industry decisions.