Lost Nuclear Legacy: The CIA's Missing Plutonium Device in the Himalayas - A 60-Year Environmental Concern

The mission ended in failure. The secret remained hidden until its revelation in 1978.

During the peak of the Cold War in 1965, China had recently tested an atomic bomb. The CIA sought to monitor Chinese missile tests by installing a nuclear-powered antenna high on Nanda Devi, providing surveillance over China's border.

American and Indian mountaineers prepared their equipment: an antenna, cables, and a 13 kg generator known as SNAP-19C containing plutonium. As the climbers prepared for their final ascent, a sudden blizzard engulfed the mountain, as reported by The NY Times.

Captain MS Kohli, the Indian officer commanding the mission, watched anxiously from the advanced base camp below. He urgently radioed: "Camp Four, this is Advance Base. Can you hear me? ... Come back quickly... don't waste a single minute."

"Secure the equipment. Don't bring it down."

The climbers concealed the equipment on an icy ledge near Camp Four and descended rapidly to survive. They abandoned a nuclear device containing nearly one-third of the plutonium used in the Nagasaki bombing.

The device has never been recovered.

The United States never officially acknowledged this mission. Officially, the incident never occurred.

The mission concept originated at a cocktail gathering. General Curtis LeMay, US Air Force commander, conversed with Barry Bishop, a National Geographic photographer and Everest climber. Bishop explained how Himalayan summits provided clear visibility deep into Tibet and China.

Shortly after, the CIA requested Bishop to organize a covert expedition disguised as scientific research. His responsibilities included recruiting climbers, creating a cover story, and maintaining secrecy.

Bishop accepted. He established the fictional "Sikkim Scientific Expedition" and recruited Jim McCarthy, a young American climber and lawyer, who received $1,000 monthly for what the agency described as an essential national security assignment.

India participated discreetly, motivated by concerns about China following the 1962 conflict. Captain M.S. Kohli, the Indian mountaineer leading the operation, was skeptical.

"It was nonsense," he later stated.

When the agency initially proposed placing the device on Kanchenjunga, the world's third-highest peak, Kohli remarked, "I told them whoever is advising the CIA is a stupid man."

McCarthy concurred. "I looked at that Kanchenjunga plan and said, 'Are you out of your mind?'" Eventually, they selected Nanda Devi instead.

The ascent began in September 1965. The climbers were transported by helicopter to high altitude without proper acclimatization. Many became ill, but the plutonium provided warmth. The radioactive fuel generated heat, causing Sherpas to compete over who would carry it, according to Kohli.

"At the time," he said, "we had no idea about the danger."

Then on October 16, near the summit, the blizzard struck. "We were 99 per cent dead," recalled Sonam Wangyal, one of the Indian climbers. "We had empty stomachs, no water, no food, and we were totally exhausted."

When Kohli ordered the equipment abandoned, McCarthy protested vehemently. "You have to bring that generator down, you're making a huge mistake," he insisted.

Nevertheless, the decision remained. The following year, the team returned to recover the device. It had vanished. The entire ledge—ice, rock, equipment—had been swept away by an avalanche.

"'Oh my God, this will be very, very serious,'" Kohli recalled the CIA officers saying. "'These are plutonium capsules!'"

Search missions followed, employing radiation detectors and infrared sensors. Nothing was found.

"That damn thing was very warm," McCarthy explained. "It would melt the ice around it and keep sinking."

The mission failed completely. The secret remained concealed until 1978.

A young journalist named Howard Kohn uncovered the story and published it in Outside magazine. The scandal erupted. Protesters in India displayed signs reading, "CIA is poisoning our waters."

Behind closed doors, governments worked swiftly to quell the controversy. President Jimmy Carter and former Prime Minister Morarji Desai collaborated secretly.

In a confidential letter, Carter commended Desai for handling "the Himalayan device problem," describing it as an "unfortunate matter."

Publicly, both nations revealed little.

Today, the men who transported the device up the mountain are elderly or deceased. Jim McCarthy, now in his 90s, still expresses anger.

"You can't leave plutonium by a glacier feeding into the Ganges!" he exclaimed. "Do you know how many people depend on the Ganges?"

Captain Kohli, before his passing, reflected with remorse.

"I would not have done the mission in the same way," he admitted. "The CIA kept us out of the picture," he said. "Their plan was foolish, their actions were foolish, whoever advised them was foolish. And we were caught in that." "The whole thing," he concluded quietly, "is a sad chapter in my life."