In our 50th anniversary year, ELI partnered with the Environmental and Energy Law Program at George Washington University School of Law to review the state of environmental law and “reimagine” what law might need to look like in the years ahead if we are to achieve a more sustainable future. Key to this endeavor were several meetings that we convened of natural resources legal scholars and leaders from the community of practitioners to discuss the critical issues that will define the next 50 years of environmental and natural resources law, starting with convenings at the Wingspread Conference Center in Racine, Wisconsin, in March 2019, and at Airlie House Conference Center in Warrenton, Virginia, in November 2019. We continued to consider the notions generated through these dialogues at policy convenings and in the research department of the Institute, leading to production of this report. Our discussions, and this report, center on several key areas of challenge in the human/environment interface, including: climate change and decarbonization, nonpoint sources of water pollution, materials conservation and reuse, and ecosystem degradation and biodiversity loss. In addition, environmental justice was seen as an area of needed focus alone as well as a point of attention that cuts across all of the other challenges. Progress in these areas will require law and policy changes at all levels of government, as well as accompanying economic, political, and social changes.