Although sometimes maligned as unduly rigid and inefficient, United States environmental laws in reality use a variety of regulatory design strategies and policy tools that are conducive to regulatory tailoring, dynamism, and improvement. These laws often call for several steps of refined regulatory judgments, and also to varying degrees embrace in their implementation use of markets or market-mimicking mechanisms. Most US environmental laws are also drafted with an array of nuanced strategies designed to lessen predictable forms of regulatory error and failure. A rich array of participatory and enforcement rights make US environmental law unlikely to be unimplemented or violated with impunity. This chapter discusses the reason for this regulatory tool diversity, highlights several different regulatory steps and structures in most laws, and the diverse strategies and tools utilized to address environmental harms and risks.