Cordillera Blanca and Cordillera Norte, Pallasca Area in Northern Ancash. Atsumi Hosono led the expedition of the Sofia Alpine Club of Jochi University. Other members were Yoshihiko Takayama, Yasuhide Yokochi and Shuzo Kinoshita. They established Base Camp on Pucaranra- cocha on July 20, but though active here from July 24 to August 23, unfavorable weather prevented their climbing either Chinchey or Copap. On the last day of August they left Huaraz for the north, reaching Corongo the same day. Base Camp was established on Akhuanccocha at 13,750 feet on September 2. Camp I (15,850 feet) was on the rock near the end of the Rosco Grande Glacier. On the 7th they all climbed Rosco Grande (5260 meters or 17,257 feet). On the 9th Yokochi and Takayama climbed a rock peak and Hosono and Kinoshita a snow peak above Camp I, both of the same altitude (16,831 feet). On the next day Takayama and Yokochi climbed a peak of 17,192 feet while Kinoshita and the Peruvian porter Pablo Morales climbed a 17,257-foot peak.
Ichiro Yoshizawa, Japanese Alpine Club