s the story of a revolution in placer mining-and its subsequent impact on the state of Idaho-from its inception in the early 1880s until its demise in the early 1960s. Idaho was the nation's fourth-leading producer of dredged gold after 1910 and therefore provides an excellent lens through which to observe the practice and history of gold dredging.

Author Clark Spence focuses on the two most important types of dredges in the state-the bucket-line dredge and the dragline dredge-and describes their financing, operation, problems, and effect on the state and environment. These dredges made it possible to work ground previously deemed untouchable because bedrock where gold collected could now be reached. But they were also highly destructive to the environment. As these huge machines floated along, they dumped debris that harmed the streams and destroyed wildlife habitat, eventually prompting state regulations and federal restoration of some of the state's crippled waterways.

Providing a record of Idaho's dredging history for the first time, this book is a significant contribution to the knowledge and understanding of Western mining, its technology, and its overall development as a major industry of the twentieth century.