A dry but useful academic study of misguided federal resource management and ecological experimentation. ``Nature preservation--especially that requiring a thorough scientific understanding of the resources intended for preservation--is an aspect of park operations in which the [National Park] Service has advanced in a reluctant, vacillating way,'' writes Sellars, a historian with the Park Service. More directly put, his study shows how the Park Service has throughout its existence allowed the preservation of endangered species and habitats to be governed by changes in administrations and political styles. Charged with the divided mission of maximizing ``recreational tourism and public enjoyment of majestic landscapes'' on the one hand, and keeping undisturbed large sections of wild land on the other, the service has generally favored the first, putting science in the backseat. Among Sellars's cases in point is a scientific survey in Yellowstone National Park that involved marking grizzly bears' ears with colored tags, a survey halted in part because tourists complained about the bears' odd appearance. He goes on to charge that as the Park Service grows in size, its ranks are increasingly filled with part-timers and ``technicians,'' not with dedicated scientists who can train the government's resources on analyzing the ecosystems under its charge. Regrettably, many of his most interesting observations are buried in his endnotes, in which he tells, among other tidbits, the story of the Park Service's transferring a mountain in Colorado to the Forest Service after a rock slide altered its face and, presumably, obliterated its scenic grandeur. Sellars does not make the reader's task an easy or pleasant one--a shame, because he has much to say to those interested in the way national resources are managed.