The company Paranapanema led the effort, assisted by FUNAI - the Brazilian government agency responsible for indigenous affairs - and the National Department of Mineral Production. The word pacification in the 1981 decree carried weight. The Waimiri-Atroari had violently resisted earlier Brazilian incursions, including attacks on road crews building BR-174 between Manaus and Boa Vista in the 1970s. Pacification meant ending that resistance, and the documentary record suggests the process involved coercive negotiation, disease outbreaks among the Waimiri-Atroari that reduced their population by hundreds, and bureaucratic maneuvers that prioritized the mining concession over indigenous land rights. The Waimiri-Atroari lost much of their legally recognized territory. What remained was legally protected but smaller. Paranapanema gained a concession covering 130,000 hectares in fourteen lots. The legal process had been followed. Whose interests it served was another question.

The deposit exceeded early expectations. In 1982, the US Bureau of Mines estimated that all of Brazil held about 67,000 tonnes of contained tin. By 1986, Pitinga alone was estimated at 575,000 tonnes of tin - nearly ten times the national figure from four years earlier. The ore body formed through a complex geological history: coarse-grained porphyritic albite granite intruding older Paleoproterozoic volcanic and pyroclastic rocks, with alluvial deposits washed into forested valleys from the primary source in the hills of the Serra da Madeira. Those alluvial deposits - easier to mine because the tin was already loose in river gravel - were the foundation of the early operation. Bucketwheel excavator dredges scooped up material rich in cassiterite and pumped it through pipes to floating processing plants. The ore was concentrated on site and shipped to the Mamore metallurgical facility in Sao Paulo state for final casting.

Running an open-pit mine 300 kilometers from Manaus required building an entire town. Mineracao Taboca constructed Pitinga village from scratch - roads, treated water, sanitation, a housing estate for 5,000 people, schools, restaurants, health facilities, a bank branch, a post office, a telephone exchange, a supermarket. By 1990, the mine employed 2,000 people directly and an estimated 40,000 indirectly through suppliers, transport, and service industries. In 1985, Paranapanema invested US$15 million in infrastructure upgrades including a 10,000-kilowatt hydroelectric power plant on the Pitinga River, expected to save US$4 million annually on diesel. For the workers who moved their families to Pitinga, the village was a job and a community, isolated but functional. For the company, it was a complete operational unit dropped into the Amazon - modular, self-contained, engineered to make mining possible in a place where nothing else was.

In 1987, the dykes of four tailings ponds failed. Mining tailings - the slurry left after ore extraction - flowed into the Alalau River, which carried the sediment downstream through the Waimiri-Atroari Indigenous Reserve. The contamination affected fish populations. The Waimiri-Atroari reported that the polluted water made them sick. It was the kind of failure that happens at remote open-pit operations with some regularity - a combination of engineering assumptions that held until they did not. Mineracao Taboca had invested in environmental systems: dams and dykes to hold tailings, drainage infrastructure, replanting programs for cleared areas, holding ponds that doubled as reserves for future processing if tin prices rose. None of it prevented the 1987 break. By March 1991, the cost of environmental recovery was estimated at US$50 million. The company committed to research with universities and research institutes to develop restoration techniques. The Waimiri-Atroari had already paid a price that no restoration program could recover.

In 2006, Mineracao Taboca began to extract ore from primary rock in place of the exhausted alluvial deposits - a more technically difficult and expensive operation, but necessary to keep the mine alive. Two years later, the Peruvian company Minsur acquired both Mineracao Taboca and the Mamore smelting facility. In November 2024, Minsur agreed to sell both assets to China Nonferrous Metal Mining Group (CNMC) for US$340 million, pending regulatory approval. The new owners inherited what independent analysts called the largest undeveloped tin deposit in the world: 420,000 tonnes of contained tin remaining in 2014, enough to supply global markets for decades. Production that year was 5,532 tonnes of tin in concentrate, with 3,256 tonnes in the first half of 2015. In August 2015, water seepage was found in the dyke of the hydroelectric plant 80 kilometers away, and operations slowed during repairs. Pitinga continues to produce, operating on land that was once indigenous reserve, supplying tin for electronics soldered together in places that know nothing of the Amazon village that makes their circuits possible. The deposit runs deep. So does what it cost to reach it.