Marco Siffredi (22 May 1979 – 8 September 2002) was a French snowboarder and mountaineer who hailed from a climbing family; his father was a mountain guide, and his older brother Pierre had died in an avalanche in their hometown of Chamonix, France. Siffredi was the first to descend Mount Everest on a snowboard, completing this feat in 2001 via the Norton Couloir. In 2002, he disappeared after making his second Everest summit, while attempting to snowboard the Hornbein Couloir; his body has never been found. First snowboard descent at Nant Blanc In his early years, Marco Siffredi made several first descents in the Chamonix valley before extending his horizons to bigger peaks. In June 1999, he made the second-ever descent of Mont Blanc on the Aiguille Verte, after Jean-Marc Boivin’s ski descent in 1989. First Everest descent Siffredi reached the summit of Everest, a 8,849-meter mountain, on May 23, 2001 with the help of oxygen along with two Sherpas who brought the equipment. 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. Instead, he rode down the Norton Couloir back to Advanced Base Camp (ABC) at the foot of the North Col. Then he began the descent down the Norton Couloir of the north face, but after 200 meters a fastening strap on his snowboard broke due to the cold . After repairing it with help from a sherpa, Siffredi continued the descent to 6,400 meters in two hours. The day before, on May 22, Austrian climber Stefan Gatt reached the summit alone and without using oxygen. He went on a snowboard up to 8,600 meters along the north wall, but at that altitude he found very hard snow and decided to continue without snowboarding. There were disputes about who would be awarded the first snowboard descent of Everest, as Gatt got out first, but did not use a snowboard for about 1,000 m. The site everestnews.com, attributed primacy to Siffredi but the site snowboarding.transworld.net, recognized merits and demerits to both, so the record was shared. Second Everest descent Early in August 2002, Siffredi departed for Nepal, intending to make the first snowboard descent of Everest along the Hornbein Couloir. It was late in the season for summitting Everest, but Siffredi hoped that the passage would have more snow. On August