Elinor Ostrom was the first woman awarded the Nobel Memorial Prize in Economic Sciences. Ostrom studied the management of shared environmental resources. Her work focused on how human beings come together to solve social dilemmas such as how a resource held in common should be managed. This edited volume builds on Ostrom's research with six chapters by renowned environmental scholars. Each chapter explores a particular issue in environmental policy by carefully analyzing how institutions impact environmental outcomes and considering what might be done to improve those outcomes. The volume begins with an examination of resource governance in the American West and how institutions developed to govern a complex and demanding landscape. It then explores the largely successful multi-stakeholder approach to the management of the greater sage grouse in the western U.S. The third chapter explores the role of American and Canadian indigenous groups in governing Pacific salmon fisheries. Chapter four examines Ostrom's response to Garrett Hardin's classic "Tragedy of the Commons," which claims that unchecked human population growth is destined for tragedy. The fifth chapter bridges the work of Gary Libecap on property rights with Ostrom's work on polycentric governance. And the sixth and final chapter explores how the development of markets for industrial byproducts helped clean up the commons. As Ostrom noted in her Nobel Lecture, "We need to ask how diverse polycentric institutions help or hinder ... the achievement of more effective, equitable, and sustainable outcomes at multiple scales." This edited volume sheds light on how allowing people to experiment with different institutional approaches results in innovative solutions to today's most pressing environmental problems.