In 1929, he met mountaineer Eric Shipton and together they climbed the twin peaks of Mount Kenya, making the first ascent of Nelion, the secondary summit. A member of Hugh Ruttledge's 1933 Mount Everest expedition, Wyn-Harris reached Edward Norton's record height of 8,573 m (28,126 feet). At around 8,460 m (27,920 ft), he discovered an ice axe, which was almost certainly a remnant of Mallory and Irvine's ill-fated attempt at the first ascent in 1924. Wyn-Harris returned to Everest in 1936, in an expedition again led by Hugh Ruttledge.