From Frederick Jackson Turner to Walter Prescott Webb, the high cliffs of Yosemite to the flat deserts and blasted rock of the Nevada Test Range, the American West has long been defined by its environments. The human history of western ecologies extends back thousands of years, writes the historian Sara Dant in her new synthesis, Losing Eden: An Environmental History of the American West (Wiley Blackwell, 2016). Dant, a professor of history at Weber State University in Ogden, Utah, traces the history of how people changed, and in turn were changed by, the American West’s myriad environments. In Losing Eden, Dant describes how pre-contact societies made water flow in the desert, how Spanish colonizers introduced fauna to the region now taken for granted as decidedly “western,” and how American commodification of the non-human world fundamentally altered human perceptions of western landscapes. By the late nineteenth century, the concept of commodification had led to both great material wealth for the United States, and almost irreparable damage to western environments. It was not until the beginning of the twentieth century that, according to Dant, some Americans began to look upon their “lost Eden” and ask, “at what cost?” Losing Eden is a book which, at heart, seeks to disprove the notion that the American West was ever an Eden at all by showing that the history of environmental change in the region is as old as human footsteps on western soil, while also arguing for a new ethic of collective action to reverse some of the most far reaching changes wrought by humans in the American West. Stephen Hausmann is a doctoral candidate at Temple University and Visiting Instructor of history at the University of Pittsburgh. He is currently writing his dissertation, a history of race and the environment in the Black Hills and surrounding northern plains region of South Dakota, Wyoming, and Montana.