["Journal of Agrarian Change, EarlyView. ", "\nABSTRACT\nThis article presents a new way of obtaining deep explanations of environmental problems. We expose the production strategies, corporate strategies and state actions that have been taken by firms and state agencies to facilitate the geographical expansion of the wood‐based commodity frontier at the expense of reindeer pastoralists among the Indigenous Sámi people. Through qualitative analysis of archival material and historical research, drawing on commodity frontier theory and a state theory of modern landed property, we explain what happened to forests on Sámi lands in northern Fennoscandia and why it happened during three historical phases: the colonial‐capitalist breakthrough, the industrial capitalist breakthrough and the intensification breakthrough. We show how these phases were critical to the appropriation and transformation of forests on Sámi lands and provide deep explanations of environmental problems for reindeer pastoralists. Finally, we discuss the relationship between commodity frontiers, different forms of landed property and the natural environment.\n"]