Intellectual and environmental history merge in a useful study of one of the world's great natural wonders. Pyne (Vestal Fire, 1997, etc.), the MacArthur Award-winning author of several books on the Grand Canyon, returns to the same setting here with this history of how the American view of nature changed as a result of explorers' encounters with the mile-deep terrestrial fissure. In the mid-19th century, Pyne writes, Americans were inclined to view such features of the landscape as challenges to be overcome, not as scenic splendors: ""popular instincts argued that river-dashed gorges were hazards, not adventures."" It was thanks to a generation of intellectuals--and especially geologists, Clarence Dutton foremost among them--that the weird, imposing land forms visible in and around the Grand Canyon would come to be seen as ""the coliseums, temples, and statuary of an inspired nature."" Until that time, Pyne notes, the canyon was known but not publicized; the project of intellectuals to claim it as a national treasure without peer in the world was a step in creating a general consciousness of public lands that would in some instances become the first national parks. Dutton wrote celebratory studies and gave exalted place names (Point Sublime, Point Imperial) to spits of land overlooking the chasm. Meanwhile, his contemporary Thomas Moran painted masterful panoramas that were widely published in journals and helped to lure tourists to the region. Later, canyon aficionados like Joseph Wood Krutch continued the call. ""The Canyon claims standing,"" Pyne concludes, ""not because of its size or antiquity but, as Dutton had insisted, by virtue of its ever-evolving ensemble and the ideas continually made available by which to interpret it."" The many ideas contained in Pyne's book alone will help that interpretation along nicely.