This report surveys recent and past decisions of the United States Supreme Court, examines their impact on the fields of environmental law and regulatory law, and evaluates how they might affect various conservation strategies. Given the present period of rapid, highly impactful change in the Court’s jurisprudence, it outlines the 50-year arc of federal environmental protection, documenting the shift from a widely held societal consensus on strong national authority to the more constrained, piecemeal approach unveiled in recent decisions.