Sixty years after a team of American and Indian climbers abandoned a plutonium-powered generator on the slopes of Nanda Devi, one of the world's most forbidding Himalayan peaks, the U.S. government still refuses to acknowledge that the mission ever happened. The device, a SNAP-19C portable generator containing plutonium isotopes including Pu-239 -- the same material used in the Nagasaki bomb -- was left behind in October 1965 when a sudden blizzard forced climbers to retreat from Camp Four, just below the summit. The mission originated from a cocktail party conversation between General Curtis LeMay and National Geographic photographer Barry Bishop, who had summited Everest in 1963. China had just detonated its first atomic bomb in October 1964, and the CIA wanted to intercept radio signals from Chinese missile tests by placing an unmanned listening station atop the Himalayas. Barry Bishop recruited elite American climbers and coordinated with Indian intelligence to haul surveillance equipment up the mountain. Captain M.S. Kohli, the Indian naval officer commanding the mission, ordered climbers to secure the equipment and descend when the blizzard struck. Jim McCarthy, the last surviving American climber, recalled warning Kohli he was making a mistake. "You can't leave plutonium by a glacier feeding into the Ganges!" he recalled. "Do you know how many people depend on the Ganges?" When teams returned in spring 1966, the entire ice ledge where the gear had been stashed was gone -- sheared off by an avalanche. Search missions in 1967 and 1968 found nothing. The device remains buried somewhere in the glaciers that feed tributaries of the Ganges River.Read more of this story at Slashdot.