High in the icy reaches of the Indian Himalayas, a decades-old Cold War secret still lies buried—both literally and figuratively. Nearly sixty years after a covert CIA mission to plant a plutonium-powered nuclear device on Nanda Devi, India’s second-highest peak, the generator remains missing, its fate shrouded in mystery and controversy. As climate change accelerates the melting of Himalayan glaciers, fresh concerns are surfacing about the potential environmental and security risks posed by this lost relic of espionage, according to The New York Times and Dawn.
The story begins in 1965, a time when tensions between the United States, China, and India were running high. China had just tested its first nuclear weapon, and U.S. intelligence agencies were desperate for any edge in monitoring Chinese missile launches. In a move that reads like a page from a spy novel, the CIA, with the cooperation of India’s Intelligence Bureau, launched a clandestine mission to install a nuclear-powered surveillance station atop Nanda Devi. Officially, the operation was disguised as a scientific expedition, but its true aim was to position a radioisotope thermoelectric generator (RTG) capable of powering an infrared imaging camera and intercepting telemetry from Chinese nuclear tests.
This generator, known as a SNAP-19C, was no ordinary piece of equipment. It contained several kilograms of plutonium-239—the same isotope used in the atomic bomb dropped on Nagasaki. Devices like it had powered NASA’s Voyager I and other satellites, but this one was meant to fuel a secret listening post in one of the world’s most inhospitable environments. American and Indian climbers, carrying the 50-pound generator, braved treacherous conditions as they ascended Nanda Devi’s slopes in October 1965.
But nature had other plans. As the team neared the summit, a violent blizzard swept in, threatening their lives. Facing the very real possibility of disaster, the expedition leader made a fateful decision: the nuclear-powered generator and its associated equipment were to be secured on an icy ledge, and the team would retreat immediately. The hope was to return and complete the mission once conditions improved.
When the climbers returned the following spring, however, the generator had vanished. Authorities believe an avalanche had swept away the ledge where it was stored, burying the device deep within the glacier. Despite multiple search missions using radiation detectors and metal sensors, the SNAP-19C was never found. The loss triggered alarm within the CIA and anxiety in both Washington and New Delhi, as the potential consequences of a missing plutonium device in the Himalayas began to dawn on officials.
For more than a decade, the operation remained one of the best-kept secrets of the Cold War. U.S. and Indian authorities, including President Jimmy Carter and Indian Prime Minister Morarji Desai, worked quietly behind the scenes to contain the fallout from the mission’s failure. According to Dawn, the episode was kept under wraps until 1978, when an investigative reporter exposed the story to the world, sparking outrage across India. Lawmakers accused the government of allowing the CIA to operate in secret on Indian soil, while protesters warned that the agency had endangered the headwaters of India’s most sacred river, the Ganges.
The environmental stakes could hardly be higher. The glaciers surrounding Nanda Devi feed into rivers like the Rishi Ganga and Dhauliganga, which in turn flow into the mighty Ganga River—a lifeline for hundreds of millions of people across northern India. While scientific studies conducted in the 1970s found no evidence of radioactive contamination and concluded that the risk was low, concerns never fully subsided. As the Himalayan glaciers melt faster due to climate change, the possibility that the device could be exposed—and its plutonium contents released into the ecosystem—has raised fresh alarms.
According to The New York Times, “the device is still believed to be buried somewhere beneath glaciers that feed the Ganges River, a lifeline for hundreds of millions of people.” Environmentalists warn that if the RTG begins to leak radioactivity into the glacial meltwater, it could have devastating consequences. The delicate ecosystem of the Himalayas is already under strain from rising temperatures, increased glacial melting, and more frequent floods and avalanches. Should the device’s protective casing be compromised, radioactive material could find its way into the water supply, with potentially catastrophic results.
Despite the passage of time and repeated assurances from officials, the controversy has never fully faded. The episode is now considered one of the most contentious intelligence operations ever carried out in India, and its legacy continues to haunt both nations. As Dawn reports, “Indian politicians, environmental activists, and villagers living near Nanda Devi have renewed calls for the device to be located and removed.” Some worry that, as glaciers retreat, the generator could eventually be exposed—or worse, fall into the wrong hands.
“If the RTG remains in its present state, keeping everything in check, the threat level remains low,” environmental experts have observed. “With time and if a leak in the RTG might allow radioactivity into glacial meltwater. As a consequence a subsequent rise in glacial melting and flood/avalanche occurrences in Uttarakhand, despite the low possibility, environmentalists have warned of this risk.”
The mission’s exposure in the late 1970s led to significant political fallout. Declassified diplomatic cables reveal that both President Carter and Prime Minister Desai worked quietly to manage the situation, but public anger was palpable. Lawmakers demanded accountability, and local villagers expressed fears for their safety and the sanctity of the Ganges. The episode became a cautionary tale about the unintended consequences of secret intelligence operations and the long shadow they can cast over international relations and environmental safety.
Today, the mystery of the missing plutonium device endures. Search teams have long since given up hope of finding the SNAP-19C, but its potential impact remains a source of anxiety. As climate change accelerates the melting of the Himalayan glaciers, the prospect that the generator could one day be uncovered—or that its radioactive contents might seep into the water supply—continues to worry scientists, environmentalists, and residents alike.
While the official line remains that the risk is low, few are willing to dismiss the possibility of disaster out of hand. The episode stands as a stark reminder of the complex interplay between geopolitics, secrecy, and environmental stewardship. In a world where the past so often collides with the present, the lost CIA device on Nanda Devi serves as a chilling symbol of both human ingenuity and the unintended consequences that can follow in its wake.
As the glaciers continue their slow retreat, the fate of the SNAP-19C remains uncertain—hidden beneath snow and ice, but never far from the minds of those who depend on the rivers that flow from the roof of the world.
