The first western explorers to discover the col were George Mallory and Guy Bullock on the 1921 British Mount Everest reconnaissance expedition although it was only Bullock who actually reached it. They were exploring the West Rongbuk Glacier in Tibet hoping it might give access to a route for reaching the summit of Everest. They named it Lho La, meaning South Pass simply because it was to the south of where they were. This rather self-centred decision was to give difficulties later, as mentioned above. Lho La gave access to Everest's West Ridge and to its Western Cwm but they thought neither of these gave feasible ways of ascent.