For almost three decades, open cut coal mines have been expanding deeper into the densely settled agricultural landscape of the Hunter Valley, New South Wales. The mines have become increasingly profitable for Australian and multinational companies, and Newcastle, the capital of the Hunter region, is now the world's largest black coal exporting port. Despite the significant new wealth that mining has brought, those residing in proximity to mines and coal-fired power stations in the Hunter Valley have long struggled against the deleterious effects on health, rural livelihoods and environment. In recent years, opposition has widened to a more activist environmentalism that links the coal economy to climate change, global warming and other cumulative health and environmental effects. The organisational scale of the opposition has correspondingly widened to interconnect local residents, Green political parties and transnational organisations such as Greenpeace and the World Wildlife Fund. Using the Anvil Hill open cut mine proposal as an example, this paper examines the shifting grounds of environmental knowledge and oppositional practices by coal-affected residents of the Hunter Valley.