# Trail designation system

(Difference between revisions)
 Revision as of 12:35, 18 June 2011 (edit)Joe (Talk | contribs) (→'''Also see''')← Previous diff Current revision (05:41, 17 August 2011) (edit) (undo)Joe (Talk | contribs) (→'''Skier Ability Slope Gradient''') (One intermediate revision not shown.) Line 12: Line 12: *Advanced Intermediate | to 50% (short pitches to 55%) *Advanced Intermediate | to 50% (short pitches to 55%) *Expert | over 50% (maximum of 80%) *Expert | over 50% (maximum of 80%) + + == '''Slope Steepness''' == + [[Image:Grades degrees.png|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.|thumb|200px]] + 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. == '''Ski trail difficulty ratings in North America''' == == '''Ski trail difficulty ratings in North America''' == Line 64: Line 80: *'''[[Mountain master planning process]]''' *'''[[Mountain master planning process]]''' *'''[[Maximum Grade]]''' *'''[[Maximum Grade]]''' + *'''[[Orography]]''' *'''[[Ski resort]]''' *'''[[Ski resort]]''' *'''[[Trail designation system]]''' *'''[[Trail designation system]]'''

## Current revision

Although slope gradient is the primary consideration in assigning a trail rating, other factors come into play — including trail width, normal snow conditions and whether or not the resort regularly Snow grooming the trail.

##  Skier Ability Slope Gradient

Skier Rider Ability Level The following gradients were used to determine the skier ability level of the mountain terrain:

Skier Ability | Slope Gradient

• Beginner | 8 to 12%
• Novice | to 25% (short pitches to 30%)
• Low Intermediate | to 30% (short pitches to 35%)
• Intermediate | to 40% (short pitches to 45%)
• Advanced Intermediate | to 50% (short pitches to 55%)
• Expert | over 50% (maximum of 80%)

##  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.

##  Ski trail difficulty ratings in North America

Ski trail difficulty ratings in North America
Trail Rating Symbol Level of difficulty Description
Green circle Easiest The easiest slopes at a mountain. Green Circle trails are generally wide and groomed, typically with slope Gradients ranging from 6% to 25% (a 100% slope is a 45 degree angle).
Blue square Intermediate Intermediate difficulty slopes with Grades commonly ranging from 25% to 40%. These slopes are usually groomed. Blue Square runs make up the bulk of pistes at most ski areas, and are usually among the most heavily trafficked.
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.
Double black diamond Expert These trails are even more difficult than Black Diamond, due to exceptionally steep slopes and other hazards such as narrow trails, exposure to wind, and the presence of obstacles such as steep drop-offs or trees. They are intended only for the most experienced skiers.

This trail rating is fairly new; by the 1980s, technological improvements in trail construction and maintenance, coupled with intense marketing competition, led to the creation of a Double Black Diamond rating.

Variations Various Variations such as doubling a symbol to indicate increased difficulty, or combining two different symbols to indicate intermediate difficulty are occasionally used. One example is a diamond overlapping a square to indicate a trail rating between a Blue Square and a Black Diamond. Mont Tremblant in Canada utilizes two blue squares right next to each other to indicate the same thing. Many resorts throughout Colorado use a double diamond with an "EX" in the center to mark a run with extreme terrain, even more difficult than a double diamond. Bogus Basin, a resort near Boise, Idaho, uses orange diamonds, which are more difficult than double black diamonds. Other U.S. resorts, such as Smugglers' Notch, Vermont, and Mt. Bohemia, Michigan, use triple black diamonds. The combination of symbols is comparatively rare at U.S. ski areas; most ski resorts stick to the standard 4-symbol progression (with the exception of the common EX runs in Colorado).
Terrain parks Various Terrain parks are whole or portions of trails that can offer a variety of jumps, half-pipes, and other special "extreme" sporting obstacles beyond traditional Mogul. The trails are typically represented by an orange rectangle with rounded corners. Usually, the terrain park will carry its own trail rating, indicating the level of challenge. A terrain park with a Black Diamond or Double Black Diamond rating would contain greater and more challenging obstacles than a park with a Blue Square rating.

##  Reference

• Wikipedia Ski trail ratings [1]