The year 2005 marked the centennial of the founding of the United States Forest Service (USFS). Samuel P. Hays uses this occasion to present a cogent history of the role of American society in shaping the policies and actions of this agency. From its establishment in 1905 under the auspices of the Department of Agriculture, timber and grazing management dominated the agency's agenda. Due to high consumer demand for wood products and meat from livestock, the USFS built a formidable system of forest managers, training procedures, and tree science programs to specifically address these needs. This strong internal organization bolstered the agency during the tumultuous years in the final one-third of the century—when citizens and scientists were openly critical of USFS policies—yet it restricted the agency's vision and adaptability on environmental issues. A dearth of ecological capabilities tormented the USFS in 1960 when the Multiple-Use and Sustained-Yield Act set new statutes for the preservation of wildlife, recreation, watershed, and aesthetic resources. This was followed by the National Forest Management Act of 1976, which established standards for the oversight of forest ecosystems. The USFS was ill equipped to handle the myriad administrative and technological complexities that these mandates required. Hays chronicles three distinct periods in USFS history, provides a summarizing “legacy” for each, and outlines the public and private interests, administrators, and laws that guided the agency's course and set its priorities. He demonstrates how these legacies affected successive eras, how they continue to influence USFS policy in the twenty-first century, and why USFS policies should matter to all of us.