Moguls are those large bumps found on some runs in snowboarding/skiing areas. They are formed by many skiiers following the same tracks down a hill. They are popular with some skiiers, for challenge factor or because it's fun to bounce around them. They are hated by most snowboarders as they are very difficult to maneuver through with a snowboard. Good boarders can do it but its not usually very fun - you can't go very fast or carve well. When they are icy they are almost impassable. Moguls are abundant on runs that aren't groomed, and when conditions are crappy.