# Black diamond

(Difference between revisions)

## Current revision

Black Diamond Difficult Amongst the most difficult at a given mountain. Black Diamond trails tend to be steep (typically 40% and up) and may or may not be groomed, though the introduction of winch-cats has made the grooming of steep slopes both possible and more frequent.

Black diamond, Difficult Amongst the most difficult at a given mountain. Black Diamond trails tend to be steep (typically 40% and up) and may or may not be groomed, though the introduction of winch-cats has made the grooming of steep slopes both possible and more frequent.

##  Slope Steepness

There are two ways of measuring slope steepness. The first is a measurement using degrees, which measures the angle of the slope in degrees from the horizontal. The second is a percentage.

There are two ways of measuring slope steepness. The first is a measurement using degrees, which measures the angle of the slope in degrees from the horizontal. The second is a percentage.

This is calculated using the formula 100*rise/run. Rise is the vertical change and run is the horizontal distance. A 100% slope is angled at 45 degrees.

• 10% is equivalent to 5.71º
• 20% is equivalent to 11.31º
• 30% is equivalent to 16.7º
• 40% is equivalent to 21.8º
• 50% is equivalent to 25.67º
• 75% is equivalent to 36.8º
• 100% is equivalent to 45º

A beginner slope is typically between 6% and 25%. Intermediate hills range from 25% to 40%, and expert is 40% plus.

##  Reference

• Wikipedia Ski trail ratings [1]