This is a chapter of a recently published book that examines how constitutional law shapes natural resources law in the United States. Following a brief background, part I identifies and discusses the various constitutional law developments affecting the scope of Congress’s power to regulate the use of natural resources. It focuses primarily on the Commerce Clause (in conjunction with the corresponding case study) and the concomitant extrinsic limits on such authority, including principles of federalism and the Tenth Amendment, as well as the diminished Nondelegation doctrine. Part II does the same for state authority and the dormant Commerce and Supremacy Clauses. Part III then examines several dynamic constitutional doctrines that tend to thwart implementation of natural resources laws, such as standing, the Takings Clause, and the Eleventh Amendment. Part IV canvasses a variety of underutilized constitutional provisions and doctrines influencing the past and future development of natural resource policy, including the Treaty, Compact, General Welfare, Due Process, and Property Clauses, and the First Amendment, and even less controversial provisions, such as the Enclave Clause. Part V concludes that constitutional law does not address natural resources law and policy except in an ad hoc fashion when the Court believes it is necessary to address some other issue—such as standing or the Eleventh Amendment. Rather than reflecting any clear constitutional thread in natural resources law, the outlook for constitutional jurisprudence in this area is a surrogate for wider debates about government regulation of human activity in the United States. At bottom are 220-year-old questions of who decides who can do what, when, and where under the U.S. Constitution.