The summary of the case indicates that the conflict between the Maine Hydroelectric Development Corporation and the town of Swanville arose when the corporation announced plans to renovate five dams on the Goose River to generate electricity. The most important part of the plan involved the use of the first of the dams (Swan Lake) not to generate power but to regulate the flow of water to the downstream dams. In 1978, the town petitioned the Federal Energy Regulatory Commission to deny Maine Hydro's application on the grounds that it would damage the environment, reduce property values, and eliminate recreational opportunities for its citizens. In the spring of 1979, the Maine Office of Energy Resources requested the assistance of an environmental mediator to resolve the dispute. The parties succeeded in reaching an agreement on the two most important and most difficult issues to resolve: the establishment of minimum and maximum lake levels and the plan for management of the area around the Swan Lake dam. Each of the mediation sessions is reviewed, with attention given to the major focus of each session, including establishing ground rules and opening proposals, separating the issues and narrowing the disagreements, problems of mistrust and poor communication, a public information meeting, and finalizing the agreements. Implications of the case are drawn for regulatory officials, communities affected by hydro development, developers of hydroelectric power, and environmental mediators. A discussion of the overall implications for the use of mediations to resolve future hydropower licensing disputes considers the potential benefits of more frequent mediations, institutional barriers to mediation, recommended actions, and implementation of recommended actions. The appendixes provide documentation relevant to the problem and the mediation process.