In his early years, Marco Siffredi made several first descents in the Chamonix valley before extending his horizons to bigger peaks.
[4] Siffredi reached the summit of Everest, the world's tallest peak, on 23 May 2001, with the help of oxygen along with two Sherpas who brought the equipment.
[6] He was forced to choose an alternative route to the one he considered the "Holy Grail" of snowboarding, as the Hornbein Couloir did not have enough snow.
[citation needed] Early in August 2002, Siffredi departed for Nepal, intending to make the first snowboard descent of Everest along the Hornbein Couloir.
[9] Siffredi ignored their warnings and after an hour's rest, began making his way towards the Hornbein just after 3 p.m. His sherpa companions lost sight of him periodically.
At the North Col, about 1,300 metres (4,300 feet) below Camp Three, both Sherpas reported seeing the distant image of a man stand up, then slide silently down the mountain.
[7][3] In autumn 2001, he climbed Shishapangma in the Himalayas (8,027 m (26,335 ft)) with the intention of making the entire descent by snowboard, but strong winds prevented the attempt.