Tree sitters. Logger protests. Dying timber towns. An iconic species on the brink. The Timber Wars consumed the Pacific Northwest in the late 1980s and early1990s and led political leaders to ask scientists for a solution. The Northwest Forest Plan was the result. For most of the twentieth century, the central theme of federal forest management in the Pacific Northwest had been logging old-growth forests to provide a sustained yield of timber. During the 1970s and 1980s, however, a series of studies by young scientists highlighted the destructive impact of that logging on northern spotted owls, salmon, and the old-growth ecosystem itself. Combining this new science with newly minted environmental laws like the Endangered Species Act, environmental activists obtained court injunctions to stop old-growth logging on federal land, setting off a titanic struggle in the Pacific Northwest to find a way to accommodate conservation imperatives as well as the logging that provided employment for tens of thousands of people. That effort involved years of controversy and debate, federal courts, five science assessments, Congress, and eventually the president of the United States. It led to creation of the Northwest Forest Plan, which sharply and abruptly shifted the primary goal of federal forestry toward conserving the species and ecosystems of old-growth forests. Scientists went from spectators to planners and guides, employing their latest scientific findings and expertise to create a forest plan for 20 million acres that would satisfy the courts. The largest upheaval in federal forest management in history had occurred, along with a precipitous decline in timber harvest, and there was no going back. In this book, three of the scientists who helped craft that change tell the story as they know it: the causes, development, adoption, and implementation of the Northwest Forest Plan. The book also incorporates personal reflections from the authors, short commentaries and histories from key figures— including spotted owl expert Eric Forsman—and experiences from managers who implemented the Plan as best they could. Legal expert Susan Jane M. Brown helped interpret court cases and Debora Johnson turned spatial data into maps. The final chapters cover the Plan’s ongoing significance and recommendations for conserving forest and aquatic ecosystems in an era of megafires and climate change.