From dirt bikes and jet skis to weed wackers and snowblowers, machines powered by small gas engines have become a permanent-and loud-fixture in American culture. But fifty years of high-speed fun and pristine lawns have not come without cost. In the first comprehensive history of the small-bore engine and the technology it powers, Paul R. Josephson explores the political, environmental, and public health issues surrounding one of America's most dangerous pastimes. Each chapter tells the story of an ecosystem within the United States and the devices that wreak havoc on it-personal watercraft (PWCs) on inland lakes and rivers; all-terrain vehicles (ATVs) in deserts and forests; lawn mowers and leaf blowers in suburbia. In addition to environmental impacts, Josephson discusses the development and promotion of these technologies, the legal and regulatory efforts made to improve their safety and environmental soundness, and the role of owners' clubs in encouraging responsible operation. Synthesizing information from medical journals, recent environmental research, nongovernmental organizations, and manufacturers, Josephson's compelling history leads to one irrefutable conclusion: these machines cannot be operated without loss of life and loss of habitat.