To avoid extinctions and other harms to ecological health from escalating climatic change, scientists, resource managers, and activists are considering and even engaging in "assisted migration" -- the intentional movement of an organism to an area in which its species has never existed. This article explores the profound implications of climate change for American natural resource management through the lens of this controversial adaptation strategy. It details arguments regarding the scientific viability and legality of assisted migration under the thicket of laws that govern natural resources in the US. The article explains why contemporary natural resource law's fidelity to historic baselines, protecting preexisting biota, and shielding nature from human activity is increasingly untenable, particularly in light of climate change. More broadly, assisted migration illustrates how the institutions and goals of natural resource law must be changed to better reflect a dynamic, integrated world. Climate change forces a radical reconsideration of the aims, foci, and standards of natural resource management.