Before revision: The double black diamond run on Blackcomb Mountain in Whistler, British Columbia, Canada, called "Couloir Extreme", which is located inside the Whistler-Blackcomb resort boundaries and can be accessed via chairlift The Norton Couloir, on the north face of Mount Everest, was descended by snowboard for the first time by French snowboarder Marco Siffredi in 2001.
After revision: The double black diamond run on Blackcomb Mountain in Whistler, British Columbia, Canada, called "Couloir Extreme", which is located inside the Whistler-Blackcomb resort boundaries and can be accessed via chairlift