Mining has proven to be a controversial form of resource development throughout the circumpolar north. This article compares two mining projects—the proposed Prosperity gold and copper mine in central British Columbia, Canada and the proposed Kallak iron ore mine in Norrbotten County in northern Sweden—that have endured long and protracted approval processes that have caused tensions and disputes between mining companies, Indigenous peoples, communities and state actors. In an effort understand the particular development paths taken by these two mining projects, this article examines the institutional determinants that structure relationships between industry, Indigenous communities and the state in Canada and Sweden. Using an historical institutionalist theoretical approach, the article focuses on the manner in which the structural features of the political systems and the environmental assessment and permitting processes in both countries have shaped the mine approval process. It also identifies particular critical junctures—important events and decisions that influenced the trajectory of the approval processes in profound and consequential ways. The article finds that institutional determinants, both historical and contemporary, have played a critical role in determining outcomes in both cases. In particular, it demonstrates the ways in which the structures of the Canadian and Swedish political systems have historically excluded Indigenous peoples from the decision-making process for resource development projects such as mines. It also shows how broader institutional contexts, as well as specific events and decisions, have complicated and politicized the mine approval processes, a situation that has heightened tensions on all sides.