Chinese Su Rongqin and Liu Yong, and Americans Tim Boelter and Jon Otto have made the coveted first ascent of Yangmolong (6,060m), a mountain with a long history of failed attempts.
In the middle section of the Shaluli Shan, in China's Western Sichuan, the Yangmolong Massif culminates in three principle peaks; Yangmolong (the eastern peak), Makara (6,030m; central peak) and Dangchezhengla (5,833m).
Until relatively recently the vast majority of exploratory trips to Sichuan's mountains came from Japan, and it was such an expedition that first attempted Yangmolong - in 1991 from the north.
Japanese returned in 2002, this time from the south, and although unsuccessful on finding a route to the highest summit, were able to make the first ascent of Dangchezhengla.
In 2007 a British attempt from the north was equally unsuccessful, though Steve Hunt, Peter Rowat and Dave Wynne-Jones were able to make the second ascent of Dangchezhengla, via a mostly new route at D.
In the meantime Koreans had been successful on Makara, trying to reach Yangmolong from the south over this summit.
This strategy, tried again by a Chinese expedition in March 2007, resulted in the death of one of the country's top climbers, Liu Xinan. There is now a memorial to him below the mountain.
A direct route to Yangmolong from the south will never be easy, and the northern aspect, as seen by Wynne-Jones, offers the best prospects. He returned in 2009, only to meet unforeseen problems.
In 2007 the approach valley had been populated by friendly, helpful, ethnically Tibetan people: two years later all this had changed. The team experienced constant hassle and serious theft of their equipment. Later, they found no safe line onto the east ridge of Yangmolong, and left dispirited, with no inclination to return.
American Jon Otto, who for many years ran a trekking and guiding agency from the Sichuan capital Chengdu, experienced similar problems later the same year.
Despite having a permit, a Chinese liaison officer, and Chinese members on his team, Otto was forbidden to continue towards Yangmolong, or else "the villagers will not be able to guarantee your safety".
Otto transferred to the friendlier south side and made two attempts, both thwarted by objective danger, though he did eventually climb a new route up the south-east face of Dangchezhengla.
Not to be put off, Otto was back again in 2010, this time pioneering a complex approach from the south-east, which would avoid any ethnic problems, but required traversing a difficult 5,100m col to reach the north side of the mountain.
From there he attempted a rock and ice spur below the summit, inspected by both the Japanese and British on their first expeditions. Heavy snowfall prevented much progress.
Not to be put off, Otto, Boelter, and Su on their third attempt, and Liu Yong on his second, returned late autumn 2011, recrossed the col, and made a difficult 400m descent on the far side. From there all four climbed the 900m spur over three days at TD, 5.6, WI3 and M4.
The ascent was in lightweight alpine-style, the team taking a further day to reverse the route. The lower section was a rock/mixed buttress, but above 5,500m the route was mostly steep, sustained glaciated slopes up to 70°.
So little is known about this area, and Otto was impressed, perhaps more so than the climbing, by small monasteries tucked high up valleys, the Tibetan livelihood and their religious practices.