In the autumn of 1965, a clandestine mission involving American and Indian climbers aimed to place a nuclear-powered surveillance device atop Nanda Devi in the Himalayas. The objective was to spy on China’s missile tests, a pressing concern for the CIA following China’s recent atomic bomb detonation. The team carried a 13-kilogram generator, SNAP-19C, containing a significant amount of plutonium, disguised as a scientific research endeavor.
As the expedition neared the summit, a severe blizzard forced the climbers to abandon the equipment. Captain MS Kohli, the Indian leader, ordered the generator and antenna secured on an icy ledge near Camp Four, instructing the team to descend for safety. This resulted in a Cold War-era nuclear device being left embedded in a sensitive mountain ecosystem, never to be recovered.
The ambitious operation originated from a casual conversation between US Air Force General Curtis LeMay and Everest climber Barry Bishop, who highlighted the strategic advantage of Himalayan peaks for observing Chinese territory. Bishop was tasked by the CIA to organize a covert expedition, recruiting climbers and establishing a cover story. Among those recruited was American climber Jim McCarthy, who was paid a substantial sum for this national security assignment.
India’s participation was driven by lingering fears from the 1962 war with China. Despite initial skepticism from Captain Kohli regarding the feasibility and safety of placing the device on high peaks, Nanda Devi was ultimately chosen. The climbers, transported to high altitudes by helicopter without adequate acclimatization, found the heat radiating from the plutonium generator a surprising comfort during the difficult ascent.
Disaster struck on October 16th as a fierce storm engulfed the climbers near the summit. Exhausted and low on supplies, survival became paramount. Despite McCarthy’s protests, Kohli’s order to abandon the equipment stood. A subsequent search the following year revealed the ledge and the device had been swept away by an avalanche. Decades later, the lost device remains a haunting reminder of a reckless Cold War mission, with concerns lingering about its environmental impact on the Ganges River watershed.
