In the United States' ski slope-classification system, double black diamond slopes are the most difficult to ski. Their steep grade, unpredictable terrain and difficult conditions require expert skiing skills.
The double black diamond rating was introduced in the U.S. around 1980, when ski resorts began opening more difficult trails for safe skiing.
Double black diamond ski slopes are steep, typically more than the 40 percent grade of the average black diamond ski slope. This means that the slope is at an angle of at least 25 degrees above horizontal.
Hazardous features, such as narrow trails, windy conditions, trees or very steep drops, often characterize double black diamond ski trails.
Because of their steep terrain, many double black diamond ski trails are not groomed, leaving snow to pile up in unpredictable drifts and moguls.
The classifications below double black diamond, ranging from easiest to most difficult, are beginner (green circle), intermediate (blue square) and difficult (black diamond).
- Photo Credit Image by Flickr.com, courtesy of Steve Jurvetson