The public trust doctrine (PTD), an ancient anti-monopoly precept of property law inherited from Roman and civil law, exists in every United States jurisdiction and several international ones. The PTD, originally concerned with navigation and fishing, has emerged as an organizing principle for natural resources management in the twenty-first century, for it posits government trustees as stewards for both present and future generations. This casebook examines the role of the public trust doctrine in managing waterways, wetlands, water rights, wildlife, the atmosphere, and uplands like beaches and parks. The materials are suited for either an upper-division environmental or natural resources law course or a seminar.

The third edition includes important new cases, including the Pennsylvania Supreme Court's landmark decision in Pennsylvania Environmental Defense Foundation v. Commonwealth, recognizing the inherent nature of the public trust doctrine in the state's constitution; the California Court of Appeal's decision in Environmental Law Foundation v. State Water Resources Control Board, extending the public trust to groundwater extraction; the North Carolina Court of Appeals' decision in Nies v. Town of Emerald Isle, recognizing the doctrine's application to North Carolina beaches, and others. It also includes a new chapter on atmospheric trust litigation, including Juliana v. United States, and a chapter compiling pioneering cases world-wide recognizing fundamental rights to ecology based on the public trust doctrine, rights of nature, and other emerging principles.