The Colorado, the claims upon its water, the politics of allocation, the very chances of sustaining life in the arid West--from the verdant headwaters of the Green River, in Wyoming, to the last ""fingerlike canals"" in Baja California, where the river no longer reaches the sea, Throughout, Fradkin, a California journalist with resource-management experience, weaves a complex, shaded pattern of interconnections--only most obviously between development of the river (for irrigation, power, resource-production, recreation) and the life-history of the seven Colorado-basin states. And while he finds much to regret or censure, this is not a lament or a tract so much as an eye-opener and, perforce, a warning. The Reclamation ethos gets a fair hearing-some so-called pork-barrel projects, we're told, ""are definite necessities."" Looking backward, Fradkin picks out the not-discreditable Mormon roots of cooperative argicultural irrigation (contingent, in turn, on Mormon identification with the arid Middle East); in the political arena, he recognizes the expertise behind the political clout of the Western ""water establishment."" Not people but cattle, we're also apprised, ""are far and away the chief beneficiaries"" of the water. (Even in California's unquenchable Imperial Valley, ""the most valuable single crop"" is alfalfa.) But as one decends the river, competition for its water increases. Before making a 280-mile dory-trip through the Grand Canyon, Fradkin visits Glen Canyon Dam: the flow of water through the river will be largely determined by the demand for air-conditioning in central Arizona, and he wants to see ""the cause-and-effect relationship"" for himself. But it's only since building of the Dam that travel through the Canyon has boomed: before, the flows were too unreliable; after, too, the conservationist mobilization against further dam-building itself focused attention on the river. Another unforeseen offshot of no-more-dam-building: a coal-burning, air-polluting power plant on Navajo land near Lake Powell. So it goes, each action or pressure triggering a response--costly to someone, somewhere. The dispersal of specific information reduces the book's viability for reference; but it remains absorbingly readable, thanks also to Fradkin's attractive, articulate presence--whether as camper or commentator.