An absorbing but diffuse narrative by an American reporter questing to penetrate the rainforest world of Brazil's nomadic gold miners, or garimpeiros. Tierney (The Highest Altar, 1989) specializes in South American wildness; here, his reporting backs up his proposition that the fevered, clandestine Amazon gold rush--far more anarchic than 19th-century rush in the American West--resembles ``the original sixteenth-century El Dorado quests of self-made conquistadors.'' With descriptive verve, he captures some arresting details--in the gold rush capital of Baiano Formiga, everything is priced in grams of gold--and meets numerous picaresque characters, like a boom-and-bust pilot who flies him into the jungle. Tierney sets some good scenes at the outset, as when, posing as a Chilean miner, he makes it to a village of Yanomamo Indians, where his yoga exercises get him tagged as a shaman; later, a search for his lost possessions involves him with the highly dubious Brazilian cops. But Tierney doesn't do enough to explain who he is and what he seeks as a writer and adventurer. So the book, despite more good stories and anthropological observations, becomes a travelogue without momentum. Tierney describes the malevolent atmosphere of a mining camp, meets a Yanomamo shaman-in-training, and accompanies a Brazilian air force operation that bombs miners' airstrips to stop the mining. He gets malaria and rests for a year, then follows the miners' destabilizing penetration into Venezuela. He helps the Macuxi Indians gather information to battle the garimpeiro invasion of the Brazilian state of Roraima. Although he concludes that the Brazilian government is right to force miners to comply with environmental laws and respect the Indian cultures, Tierney recognizes the romance and attraction of the gold rush--and that the work for many garimpeiros is better than ``urban wage slavery as it currently exists in Brazil.'' Entertaining, but it could've added up to more.