The history of America’s precious metal mining booms is well known: Sutter’s Mill, the Comstock Lode, the Black Hills. The history of America’s base metal mining booms is not well known: La Motte, Fever River, Granby. We can easily understand why thousands of miners set out in search of gold and silver. It is harder for us to understand why thousands of prospectors and small-scale miners set out in search of lead, iron, and zinc. And yet they did, often opting to mine cheaper base metals rather than join contemporaneous precious metal rushes. This lecture examines the choices, ambitions, and careers of the miners who produced the base metals that were essential to American industrial development in the nineteenth century.