Ten members of Neuchâtel Section of Swiss Alpine Club attempted unclimbed North East summit of Istor-O-Nal from north side during summer 2000.
Base camp was settled on July 11th at 4250 m, on South Udren Glacier. This glacier is wrongly named South Atrak Glacier on all mountaineering maps, initially issued by Japanese climbers. As local people corrected us about this mistake, we hereby convey the information. Camp 1 was established on July 13th on the upper section of the glacier, 5km south west from BC, at 4700m. Camp 1 was more used as an advanced BC since it was set at the beginning of mountaineering difficulties.
The only known previous attempt on this mountain was made by a Japanese team in 1977, in which they attained an altitude of 6500m. They climbed an easy but very dangerous couloir that leads to a small col between north ridge and the unnamed 6241m peak that stands right in front of Istor-O-Nal north side. As this couloir was seriously threatened by at least 10 suspended glaciers, we chose to climb a western rocky spur of the said unnamed peak. Having placed 1200 m fixed ropes on this steep spur, we finally found a flat place on top of ridge, below the unnamed summit, for setting camp 2 on July 29th.
From there, we abseiled 70m down to reach upper part of the Japanese couloir, and could eventually get to the 6000 small col. Camp 3 was settled on August 9th at the height of 6300m on the north ridge that leads to the Istor-o-nal North East summit. The lower section of the ridge was the hardest part of the route. This sharp ridge is only made of steep rock towers, ice walls and big snowy cornices, so we fixed again 500m ropes. Above C3 the ridge became easier and at 6800m, we established camp 4 on August 19th.
As fixed ropes between C1 and C2 were cut by a big stone avalanche that occurred August 18th, only 4 members found themselves at C3 and above. From thereon they had no more food and equipment supplies from below, so they opted for a rapid summit attempt on August 21st.
From the upper part of the ridge, they crossed a steep slope on the left, below the summit buttress, and climbed a couloir that lies 400m below the summit. From there, they climbed final snow slope but found it steeper and harder they thought. Also temperature was extremely cold, recorded minus 30°C inside the tent of C4 that morning. Progression became slow as they assured almost each pitch. Two members were starting to have frozen feet when they reached a point of 7170m high. Summit was right there but it would have taken 2 more hours to get it. At 4 p.m. they decided to not venture higher in regard of frozen feet and started to climb down. At 7 p.m. with the falling night they divided themselves between C4 and C3. The day after having no more valuable food and feeling hurting feet they abandoned the climbing as well as the others members also because of time running out.
Team was composed by Simon Perritaz expedition leader, Jean-Claude Lanz, André Geiser, André Müller, Albertino Santos and the four summit attempt members Antoine Brenzikofer, Christian Meillard, Jean-Michel Zweiacker, Yann Smith. On July 19th , member Thierrry Bionda broke his Achilles' heel while walking on lower glacier and had to be repatriated to Switzerland, 5 days later.