Cheatgrass (Bromus tectorum) is an exotic species that appeared in North America in the late nineteenth century and has since become a dominant plant in the arid and semiarid rangelands between the Sierra Nevadas, Cascades, and Rocky Mountains. It is the first grass to appear after the region's long, cold winters and thus has become an important forage plant for livestock and wildlife. Cheatgrass is also a major environmental hazard in the sagebrush plant communities where it has established itself, providing highly combustible fuel for the wildfires that have ravaged so much of the Great Basin since the mid-twentieth century. Cheatgrass is the first comprehensive study of this highly invasive plant that has changed the ecology of millions of acres of western rangeland. Authors Young and Clements have researched the biology and impact of cheatgrass for four decades. Their book addresses the subject from several perspectives: the history of the invasion; the origins and biology of cheatgrass; its genetic variations, breeding systems, and patterns of distribution; its impact on grazing management; and the role it plays, both positive and negative, in the lives of high desert wildlife.