In 1883, he and Emil Boss took part in the first climbing expedition in the Himalayas, led by William Woodman Graham. Among others, they claimed a near ascent of Dunagiri (reaching about 6,900 m) and an ascent of Changabang (6,864 m, 22,520 ft) in July in the Garhwal Himalaya. These claims are widely disputed and were probably based on poor maps and a misunderstanding of their location. However, their ascent to 30 feet below the east summit of Kabru south of Kangchenjunga in October of that year is now considered quite likely. Before this time, no one is known to have reached over , though it is possible that Incas reached the summit of Aconcagua (6,962 m, 22,841 ft) in Pre-Columbian times. Kaufmann, Boss and Graham therefore likely broke the world altitude record in mountaineering by 350 m or 550 m and held this record for 26 years, until the Duke of the Abruzzi's expedition to the Karakoram in 1909 reached an altitude of ca. .