The first world cup ski event of the year was at Sölden Austria. The women Giant Slalom competitors skied a run that had a portion of the course on what was characterized as a steep headwall by the competitors. the grade on that headwall was repeatedly reported as being 61%.
What is grade? Simply put percent grade = 100 *(rise/run). So, with a 61% grade on a ski slope you will drop 61 feet for every 100 horizontal feet traveled. However, when it comes to angles we are conditioned to think in terms of degrees. So, how many degrees off of horizontal is a grade of 61%? Simply pull out your scientific calculator and take the arctangent of .61 and you will see the slope is about 31° up from horizontal.
Still not impressed? I have a calculation in the works that shows how much speed a skier can get on a 30° slope and that impresses.