Perlilla, Cordillera Blanca and Yerupajá, Cordillera Huayhuash. The Shibaura University of Engineering expendition was led by Ko Kato and composed also of Yukio Ohe, Takashi Suzuki, Motoaki Ishinabe, Akira Kurihara, Tokeo Umehara and Hiromichi Miyahara. After leaving Huaraz on July 3 they entered the Quebrada Honda. From Camp I they worked for three days fixing ropes on an ice wall. On the 14th Ohe, Suzuki, Ishinabe, Kurihara and Miyahara reached the highest summit of Perlilla (18,330 feet) via the col to the south. After that they moved their base and made the first ascent of the Nevado Chacchinpus (17,586 feet) and its Number 5 Peak. (These are not identified. We suspect they may be Chacchipuncu (17,323 feet) and a neighboring peak. — Editor.) They then went to the Huayhuash where they completed the fourth ascent of Yerupajá, the third by the southwest ridge. Base Camp was at 13,125 feet, Camp I at 16,400 feet, Camp II at 18,700 feet and Camp III in a snow cave at 20,675 feet. On August 16 the first attack failed. On the 23rd Suzuki, Ishinabe, Kurihara and Miyahara reached the south summit. The first two reached the summit of Yerupajá (21,765 feet) on August 24, with bivouacs the night before and after.
Ichiro Yoshizawa, Japanese Alpine Club