Most climbs over 8,000 m without supplementary oxygen

Denis Urubko (Kazakhstan/Russia) has made 20 ascents of mountains over 8,000 m (26,246 ft) without the use of bottled oxygen, starting with Everest on 24 May 2000 and finishing with Kangchenjunga on 19 May 2014. His busiest year was 2001, when he summited Lhotse (23 May), Gasherbrum I (13 August) and Gasherbrum II (18 August).

At the time, Urubko (b. 29 July 1973) was only the fifth person to climb all 8,000ers without supplementary oxygen.

In 2019, he and fellow climber Adam Bielecki were named National Geographic Adventurers of the Year following their winter expedition to K2, which they abandoned in order to assist stricken climbers on nearby Nanga Parbat. Had they completed their climb, they would have been the first people to summit K2 in the winter; however, they sacrificed the chance of the record in order to save the life of a fellow mountaineer, as they were the only sufficiently qualified – and acclimatized – climbers in the region.