Extreme skiing is performed on long, steep (typically from 45 to 60+ degrees, or grades of 100 to 170 percent) slopes in mountainous terrain. The French coined the term 'Le Ski Extreme' in the 1970s. The first practitioners include Swiss skier Sylvain Saudan, who invented the "windshield wiper" turn in the mid-1960s, and in 1967 made the first descents of slopes in the Swiss, French and Italian Alps that were previously considered impossible. Saudan's 'first descent' in America was at Mt.