I know hardly anything about birds or trees or wild animals,"" Fox matter-of-factly writes; and it is a serious handicap for a biographer of John Muir (1838-1914), prophet of human oneness with nature, and for a chronicler of wildlife protection and wilderness preservation. But equally problematic is the book's attempt to do double-duty as a psychologically interpretive life of Muir and a general history of the American conservation movement. Muir was an odd, mesmerizing personality whose rapt sojourn in the Sierras led--through his effect on Emerson and TR, and his writings--to the safeguarding of Yosemite (and the founding of the Sierra Club); to Fox, he is the product of ""unresolved polarities""--between ""people and nature, civilized constraints and wild freedom, love and loneliness."" Though the scheme has some basis in the pattern of Muir's early years, Fox applies it heavy-handedly--spending pages, for instance, on his halting entrance into married/""civilized"" life. Still, his portrait of Muir is suggestively filled out from newly-available sources. But he also sees Muir as shaped, by those ""internal tensions,"" into ""the central figure in the history of American conservation""--hence his suitability as an entrÃ‰e to the subject. The problems with this approach are manifold. As Fox recognizes, the movement has been marked by conflict between ""savers,"" or preservationists, like Muir, and ""users,"" or conservationists, like his nemesis Gifford Pinchot, first head of the US Forest Service; and the conservationists, as Fox is aware, were not only first on the scene, they dominated the movement throughout most of its history. While it is perfectly acceptable for Fox to be a Muir partisan, it is distortive in a ""general history"" to omit struggles that preceded his efforts to save Yosemite, to largely disregard the widespread recoil from destruction that undergirded both sides' efforts, to then construe environmental issues as a fight between ""white hats and black hats""--equating conservationists with bureaucrats, and virtually with commercial interests. Muir, on the other hand, is the ""amateur radical""--from whom all worthies are descended. Given those caveats, it is particularly regrettable that Frank Graham's far more balanced and expressive history of conservation, Man's Dominion (1971), is no longer in print. Fox, in fact, concentrates so much on the rivalries between the various conservation groups, and their internal ruptures, that one has trouble bearing with them. But there is a vast amount of factual material here; and the book will have its dual, if mismatched, uses.