How have scholars tried to explain marked union membership decline in the Global North, and how have they assessed consequent “union renewal” strategies? In this journal in 2020, Bowden argued that most accounts of unionism failed to explain decline, relied too much on state policy as causation and were too optimistic about those renewal strategies. One way to respond to these important general claims is to assess, as this article does, a striking and important local instance of decline and unsuccessful strategy – Pilbara unionism, once an archetype of mining workers’ power – and to do so over the entire history of an industry. In explaining the fall of the Pilbara mining unions, which for 20 years until 1986 had seemed so strong, “power resources” and geography itself were remade by capital in ways that were entwined with, but did not always rely on, state action. This argument recasts debate about decline in two ways: by drawing on a longer timeframe than is common in industrial relations scholarship and by adopting a more theoretically explicit, and inter-disciplinary, framing than is usual in the labour historiography addressing these issues. The explanation offered here shows how, after just 20 years of mining, union power in the Pilbara unravelled. Employer strategy, the precise nature and timing of state intervention, and the geographically textured nature of employer and union power explain the rise and fall of these unions.