In 1975, he made his first solo winter ascent of the north face of the Grandes Jorasses via the Shroud (Le Linceul). In January 1977, he attempted a winter solo ascent of the Matterhorn, but failed due to a storm. However, he was successful on his second attempt in December of the same year. He soloed the Grandes Jorasses again in January 1978 (the Croz Spur), and then the north face of Eiger in March 1978, thereby becoming the first mountaineer to solo all three of the trilogy (the north faces of the Matterhorn, Grandes Jorasses and Eiger) in winter.