Makalu in the context of 1960–61 Silver Hut expedition

The 1960–61 Silver Hut expedition, formally known as the Himalayan Scientific and Mountaineering Expedition, was initiated by Edmund Hillary and Griffith Pugh with John Dienhart of World Books in America (producers of a children’s encyclopedia). The expedition lasted from September 1960 to June 1961.

In 1958 Hillary and Pugh had discussed whether Everest could be climbed without oxygen; with improved acclimatising by wintering at, say, 20,000 feet (6,100 m) for six months beforehand. Pugh’s plans, involving two bases on Everest (Base camp, and on the Western Cwm at 20,000 feet (6,100 m)), had been dropped by Hillary, as the Chinese had rebuffed their request for additional bases due to political conflict with Tibet. The expedition was also short on funds; Hillary wrote to Pugh in 1959 "I’m damn certain that we’d get someone on the top (of Everest) without oxygen but we’d need a lot of cash". In 1959 Hillary was awarded the Explorer of the Year Award by Argosy magazine; his prize was $US1000 and a trip to New York to address the award banquet. His speech and personality impressed Dienhart, who invited him to their Chicago headquarters. Hillary proposed a "Yeti search" plus a party of climbers who would winter for the first time at (20,000 feet (6,100 m)) and then attempt the summit of Makalu (27,790 feet (8,470 m)) without oxygen. Hillary estimated the expedition cost at $US120,000 and, after meeting him in Chicago in October 1959, the World Book board gave him $US125,000 and a "practically free hand".