The pristine upper reaches of the Indian Himalaya hold a deadly secret. Somewhere on the slopes of Nanda Devi, one of India’s most sacred mountains, lies a SNAP generator filled with plutonium-238. This nuclear power pack, lost during a 1965 CIA spy mission, remains missing to this day. If the plutonium deteriorates and leaks into the headwaters of the Ganges River, millions of people could face radioactive contamination of their primary water source.
China detonated its first nuclear weapon in October 1964, sending shockwaves through Washington. American intelligence agencies scrambled to understand the full scope of Chinese nuclear capabilities. Traditional spy planes risked triggering an international incident, and nobody wanted to repeat the U-2 disaster with China. The CIA needed a different approach.
The solution emerged from an audacious plan to place nuclear-powered monitoring stations high in the Himalayas, where they could track Chinese atomic weapons testing. Pulling off such a mission required America’s best mountain climbers. In 1965, the CIA approached 14 accomplished mountaineers with an offer that proved hard to refuse: $1000 a month, a free exotic trip to India, an exciting climb, and what the agency called a modest patriotic benediction.
For climbers accustomed to scraping by between expeditions, the money represented financial security. The roster included some of American mountaineering’s biggest names from the 1963 Everest expedition. Captain M.S. Kohli of the Indian Navy, working with India’s Intelligence Bureau, would lead the Indian contingent. Among the Americans, opinions about the mission varied wildly.
One climber viewed the offer as serendipitous luck. He was juggling two jobs to support his family through graduate school when the CIA money arrived like a windfall. Another brilliant student had been a track star at Harvard but gave up academia for his determination as a climber. He pushed through an enormously painful fracture on Mount McKinley just to prove himself worthy. Both the climber and the CIA were mutually impressed. There were few times in a man’s life when he could truly say he was the right man for a job, and this climber believed Operation HAT was his moment.
A second American became equally committed. This engineer and inventor was openly patriotic and viewed the CIA project as a summons to serve his country. He guarded his involvement with such dedication that friends said he never told his wife the full story.
At the heart of the operation sat a SNAP generator, weighing about 125 pounds. Inside the pack, the latest CIA technology used plutonium-238 to produce electricity for the tracking station. A thin fuel rod running through the generator’s core would reach different temperatures at different points, creating an imbalance that generated power. According to CIA specifications, the electronic box could function for 75 years or more, sending telemetry data to analysts monitoring Chinese nuclear activity from a base station 40 miles away.
Nanda Devi became the primary target for the first monitoring station. At 25,645 feet, it ranks among India’s highest peaks. For millions of Hindus, the mountain represents a sacred place, named for a goddess worshipped across northern India. For the CIA, it offered commanding views toward China’s Sinkiang province, where intelligence suggested major nuclear facilities operated.
Fourteen climbers signed on, though ultimately only nine Americans participated. Kohli’s team of India’s best mountaineers joined them, along with porters, creating a multinational expedition that launched in September 1965. Progress went smoothly until razor-sharp winds and unseasonal storms forced a critical decision. Winter was approaching faster than anticipated. Rather than risk their lives, the climbers secured the SNAP generator on a ledge, marked its location carefully, and descended.
Spring 1966 brought the expedition back up Nanda Devi’s slopes, ready to complete the mission. When they reached the cached equipment location, they found nothing. An avalanche had swept the ledge clean. Somewhere under tons of snow and ice, the plutonium-powered device lay buried. Extensive searching turned up no trace.
Dr. Arthur Tamplin, a biophysicist with the Atomic Energy Commission, delivered a grim assessment. The lost device posed a serious threat. The Nanda Devi Sanctuary sits at the headwaters of the Rishi Ganga, a narrow, violent gorge that crashes 9000 feet down into the Alaknanda River. From there, the water flows directly into the Ganges, providing drinking water and irrigation to hundreds of millions of people across northern India. If the plutonium canister cracked or corroded, radioactive material would travel a direct line from the sanctuary to the people. No barrier would stop the contamination from reaching one of the world’s most important river systems.
Despite the disaster, the CIA pushed forward with a second attempt. Nanda Kot, a neighboring peak at 22,470 feet, became the new target. Code-named Red Mountain, it offered similar surveillance capabilities. A new recruit arrived in New Delhi in March 1967, weeks ahead of his teammates. Indian officials had added elaborate security precautions for this mission.
After a hushed conference, the solution presented was bizarrely simple: Man-Tan, an American drugstore potion that fabricates a suntan. The CIA radio operator would darken his skin to a carotene-brown tone, supposedly allowing him to blend into crowds. The absurdity of the disguise highlighted how far the agency would go to maintain operational security.
Military trucks moved the climbers through late-night darkness to a base, then helicopters ferried them to a remote camp. This time they carried a substitute plutonium-fueled device, determined not to repeat the previous disaster. Bad weather plagued the ascent, and an avalanche nearly killed two climbers. Days of cautious progress finally brought success. At 21,000 feet on the north ridge, they placed the monitoring station and confirmed it was operational. The frosty air hummed as the antenna scanned the northern horizon.
A year later, winter storm damage forced another expedition to repair the device in spring 1968. That mission succeeded, but circumstances were shifting. Bill McNeff, the agent in charge of Operation HAT, was terminated in early 1967. Most climbers liked McNeff’s Irish street-kid attitude and felt he was unfairly scapegoated for the Nanda Devi disaster.
By 1968, technology had rendered the dangerous Himalayan stations obsolete. The U.S. had launched new surveillance satellites capable of monitoring Chinese nuclear activity from orbit, eliminating the need for mountaineers risking their lives in the death zone.
Silence surrounded the operation until May 1978, when Rolling Stone magazine published Howard Kohn’s expose. Two Congressmen, John Dingell and Richard Ottinger, immediately demanded a full investigation. They wrote to President Carter, expressing serious concern about allegations that the CIA had operated without public knowledge or parliamentary approval in India, potentially contaminating the Ganges River system. Copies went to the Indian Ambassador, Secretary of State Cyrus Vance, and CIA Director Stansfield Turner.
India’s response mixed shock with anger. While Captain Kohli and the Intelligence Bureau had been deeply involved in planning and execution, the operation had proceeded without public knowledge or parliamentary oversight. This arrangement allowed India to maintain its non-aligned status during the Cold War while secretly cooperating with American intelligence. The revelation forced uncomfortable questions about what Indian officials at the highest levels actually knew and when they knew it.
For participating mountaineers, the publication brought mixed emotions. The climber who had spent part of his year vacationing at a Swiss Alps ski lodge was never called upon for actual Himalayan duty. He viewed the entire experience as a rare chance for a free adventure. Most others shared similar perspectives.
But the two most committed climbers felt differently. Both believed they had served their country during a critical moment. The track star from Harvard, who had sacrificed so much to prove himself worthy, later wrote that he could genuinely say he was the right man for that job. The engineer and inventor never wavered in his conviction that the mission mattered.
British climber Chris Bonington sought information about the project when preparing to climb Changabang, another peak in the same cluster. He wanted to know about potential radioactive contamination but refused to discuss project details publicly, saying only that he wanted to know what the territory was like.
After their service ended, the Americans from the successful 1967 expedition returned to civilian life. One opened a TV repair shop, another went into outdoor equipment sales and manufacturing, and a third took up filmmaking. The Pentagon had plans for at least one of them, offering an astronaut’s uniform. After five overseas trips and 18 months away from home, he preferred a career in academia.
The lost SNAP generator on Nanda Devi has never been recovered. Decades have passed since the 1965 avalanche buried the device somewhere in the headwaters of the Ganges. Whether the plutonium canister remains intact or has corroded and leaked into the river system remains unknown. The CIA attempted several recovery missions, all unsuccessful. The device sits somewhere under ice, rock, and snow, its exact location a mystery, its condition unknowable.
Modern analysis suggests the plutonium-238 will remain radioactive for centuries. If the device fractured during the avalanche or has since deteriorated, trace amounts of radioactive material could be entering one of the world’s most sacred and vital waterways. Regular monitoring of the Ganges has detected no unusual radiation levels, but the river’s vast volume could dilute small contamination to undetectable concentrations while still posing long-term health risks.
India has restricted access to Nanda Devi Sanctuary since the 1980s, though officially for environmental conservation rather than radiation concerns. Few hunters have ever been allowed access to what may be India’s only remaining inviolate range for the rare Himalayan blue sheep. Livestock do not compete for vegetation there, and the area remains pristine. The CIA’s ill-fated mission inadvertently created one of the most closely guarded wilderness areas in the Himalayas.
CIA FILES
https://www.cia.gov/readingroom/docs/CIA-RDP81M00980R001200070033-6.pdf
