In the United States, debate over the responsibilities of different levels of government are framed within our system of constitutional federalism, which divides sovereign power between the central federal administration and regional states. Dilemmas about devolution have been erupting in all regulatory contexts, but environmental governance remains uniquely prone to federalism discord because it inevitably confronts the core question with which federalism grapples—“who gets to decide?”— in contexts where state and federal claims to power are simultaneously at their strongest.