Minnesota has mined iron for well over a century, and it is still the largest producer of iron ore and taconite in the United States. Now the state is at the center of a bigger question: should it open a second kind of mining, for copper, nickel and other metals, in some of its most water-rich landscapes? This Explainer is part of a series designed to help people understand how the government — and the people we elect to it — serve the common good with the decisions they make about policy and funding priorities that impact the interconnected whole.