Thamserku, North Face. In 1979 Japanese failed to climb the north face of Thamserku (6608 meters, 21,680 feet) when one member fell ill. In 1980 the leader Koji Okano and Katsuyuki Masunaga returned accompanied by Kimio Takehara and Dr. Keiichi Hayama. They established Base Camp on the Phunki Glacier at 12,800 feet on March 25 and Advanced Base at 16,250 feet under the central buttress on March 28. Repeating last year’s route, bivouac snow caves were made at 18,700 and 20,000 feet. Only Okano and Masunaga climbed high since the other two suffered from the altitude. On August 20 they reached 21,325 feet but returned to Base Camp. They climbed on the 24th to 18,700 feet. They then climbed the rest of the north face and three very difficult pitches on the east ridge to reach the summit at four P.M. on April 25. A full account is in Iwa To Yuki 77 with photographs and a map.