The expedition to Cho Oyu in 1959 was noteworthy not just because it consisted of female climbers but also because it was international: besides the French Kogan it included the British Dorothea Gravina and the Belgian Claudine van der Straten-Ponthoz. In 1954, Kogan, with Raymond Lambert, had been forced to turn back 500 meters from the summit, and she was eager to prove herself.