Not ready to let Gangkhar Puensum get away, in 1998, a Japanese team attempted to climb the mountain by approaching it from Tibet (China claims that half the peak falls within its territory). But Bhutan protested, and the team had to abandon its bid under somewhat mysterious circumstances. As mountaineer Tamotsu Nakamura later wrote: “As I cannot disclose an inside story behind the sudden cancellation, I write only that the reason why the permit was withdrawn was because of a political issue with [the] Bhutan government.” Rather than go home empty-handed, Nakamura and his climbing partners turned to Liangkang Kangri (also known as Gangkhar Puensum North), a 7,441m (24,555ft) unclimbed peak that is firmly planted in Tibet. Although that effort was a success, it was a disappointing end to the trip. As Nakamura later wrote, “I regret that Liangkang Kangri is not an outstanding summit.”

The world’s second highest unclimbed mountain – Muchu Chhish, a 7,452m (24,591ft) peak in Pakistan – however, might be scaled this summer. Peter Thompson, a mountaineer based in Derbyshire, England, will depart for Muchu Chhish on 4 August. Thompson and his team, learning from others’ unsuccessful attempts at the mountain, have decided to tackle it by spending the night at 5,700m (18,810ft) rather than making one day-long push for the summit. “I don’t know what our chances of success are, though they’re probably not hugely great,” Thompson says. “But we’re going to try.”

Thompson, who has climbed eight previously unclimbed peaks in Pakistan, values the exploratory aspect. As such, he readily admits that he seeks the easiest, most direct route to the summit. This doesn’t mean unclimbed mountains can’t be dangerous or challenging, however. Accidents can happen on any mountain, but at least on heavily climbed peaks detailed information is available about potential hazards, such as Everest’s Khumbu icefall or Mount Washington’s unpredictable weather and hurricane-force winds. Knowing about these dangers ahead of time can help prepare for them. For first ascents, on the other hand, the risks are uncertain and can sometimes prove deadly. “You have to step into the unknown,” Griffin says. “So you never know what you’re going to come up against.”

Improving technology

Consider Joe Puryear, a top climber from Washington who built a reputation for making first ascents of difficult routes in Alaska and the Pacific Northwest. In 2010, Puryear died while attempting to scale Labuche Kang – a mountain in Tibet that had only ever been climbed once before. He was attempting a new route, and broke through a cornice, fatally plummeting some 450m (1,500ft) to the glacier below.

Unlike previously climbed mountains, virgin peaks have no pre-laid route. No ladders or ropes exist to help guide the way, and dead ends and unexpected obstacles can stall progress. While fatalities do sometimes occur on these vertical labyrinths, more often the expeditions simply end in failure. In 2003, for example, Moss attempted to scale an unclimbed peak in Kyrgyzstan with a few university buddies and “failed miserably.” Half way up the mountain, the team couldn’t find anywhere to put their tents so they had to dig a nine-inch platform into the snow and wait out the night “sitting bolt upright on that steep step, terrified of falling down.” To make matters worse, the situation was so precarious that they couldn’t safely melt snow for drinking water. When the sun finally came up, the dehydrated, exhausted climbers decided to call it a day.

When things do work out, however, the victory is something to be especially savoured. “It’s obviously a great feeling to reach the top of any mountain, whether there’s 1,000 people there or whether you’re the first,” says Moss, who has climbed two previously unclimbed peaks in the Russian Altai Mountains. “But for me, the idea of being the first person to put foot on a bit of land was quite special.”