The following is the Cross Country Ski Trail portion of the NEW Trails Handbook. I think it’s more confusing and complicated than the old version. Their tables don’t reference the commonly used trail difficulty levels. I’m quite sure however that Easiest is Trail Class 4, More Difficult is Trail Class 3, and Most Difficult is Trail Class 2. The Handbook is located at:
http://www.fs.fed.us/im/directives/fsh/2309.18/2309.18_20.doc

23.31 – Exhibit 01

CROSS-COUNTRY SKI DESIGN PARAMETERS

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent¹.  Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use CROSS-COUNTRY SKI		Trail Class 1	Trail Class 2	Trail Class 3	Trail Class 4	Trail Class 5
Design Groomed Width	Single Lane	Typically not designed or actively managed for cross-country skiing, allow use may be allowed	2’ – 4’ Typically not groomed	6’ – 8’ Or width of grooming equipment	8’– 10” Or width of grooming equipment	Typically not designed or actively managed for cross-country skiing, although use may be allowed
	Double Lane		6’ – 8’	8’ – 12’	12’ – 16’
	Structures (Minimum Width)		36”	36”	36”
Design Grooming and Surface^2	Type		Generally no machine grooming	May receive occasional machine grooming for snow compaction and track setting	Regular machine grooming for snow compaction and track setting
	Protrusions		No protrusions	No protrusions	No protrusions
	Obstacles (Maximum Height)		12” Uncommon	8” Uncommon (no obstacles if machine groomed)	No obstacles

23.31 – Exhibit 01--Continued

Designed Use CROSS-COUNTRY SKI		Trail Class 1	Trail Class 2	Trail Class 3	Trail Class 4	Trail Class 5
Design Grade^2	Target Grade		5% – 15%	2% – 10%	0% – 8%
	Short Pitch Maximum		25%	20%	12%
	Maximum Pitch Density		10% – 20% of trail	5% – 15% of trail	0% – 10% of trail
Design Cross Slope	Target Cross Slope		0% – 10%	0% – 5%	0% – 5%
	Maximum Cross Slope (For up to 50’)		20%	15%	10%
Design Clearing	Height (Above normal maximum snow level)		6’ – 8’	8’ Or height of grooming equipment	8’ – 10’
	Width		24” – 60” Light vegetation may encroach into clearing area	72” – 20”’ Light vegetation may encroach into clearing area	96”’ – 168” Widen clearing at turns or if increased sight distance needed
	Shoulder Clearance		0” – 6”	0” - 12”	0” – 24”
Design Turn	Radius		8’ – 10’	15’ – 20’ Or to accommodate grooming equipment	≥ 25’

¹   For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

²   The determination of the trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential and other factors contributing to surface stability and overall sustainability of the trail

Application considerations for Cross-Country Ski Design Parameters:

1.  Trails with a Designed Use of Cross-Country Ski are Snow Trails that are designed and managed for travel during the snow season.  They may, however, overlap a Standard Terra Trail that is managed for use when there is no snow.  When this overlap occurs, identification of the applicable Design Parameters should be based on consideration of both the Designed Use for the Standard Terra Trail and the Designed Use for the Snow Trail.  From the two Designed Uses, select the Design Parameters with the most demanding design, construction, and maintenance requirements (sec. 14.4). 

2.  Locate or review potential locations for cross-country ski trails during the winter months.

3.  Locate cross-country ski trails where reliable snow conditions exist for 2 to 3 months annually.  Utilize topography to extend the period of snow cover.  Consider the direction the slope faces, prevailing wind direction, shade, and microclimate when locating cross-country ski trails. 

4.  Avoid avalanche hazards.  Consult with those knowledgeable of local avalanche hazards before developing cross-country ski trails.

5.  Avoid hazardous stream and lake crossings.  Normally, 6 inches of hard blue ice is considered safe for cross-country ski trail crossings.

6.  Avoid locating trails under dense canopies, especially in tall, old-growth stands.  Canopies intercept much of the snowfall, and when the air temperature rises, large chunks of snow fall on the trails.

7.  Similar to downhill ski runs, cross-country ski trails are rated as easiest, more difficult, and most difficult.  Always design trails rated as easiest for novice skiers under normal snow conditions.  Design trails rated as most difficult to provide challenges, but no unusual difficulties, for experienced skiers.  Design more difficult trails to fall between these two extremes.

8.  Provide only sweeping curves, rather than sharp turns, on downhill sections.  Locate sufficient distance at the base of downhill runs to permit the user to slow down before turning.  A place to stop adjacent to the trail mid-slope is desirable on long downhill runs.

a.  Trail Width.  Widths of trails with a Designed Use of Cross-Country Ski vary depending on the terrain, steepness of the trail, sharpness of curves, amount of use, and number of tracks.  On flat or gently rolling terrain (with grades of up to 3 percent), clear single-track groomed trails to a width of 6 to 8 feet and double-track groomed trails to a width of 10 to 12 feet.  Steeper, uphill sections should include extra clearing width where herringbone or sidestep skiing techniques might be used.  The extra clearing width should be one-half times the normal width, up to 14 feet.  Downhill sections require extra widening commensurate with the speed allowed by the hill.  The lower portions and runout require the most widening, while the upper portions require the least.  Normally, a downhill run is cleared to 1.5 times the normal width from approximately one-third to two-thirds of the way down the hill.  From two-thirds down to the bottom and through the runout, clear the trail to twice the normal width. 

b.  Trail Length.  Accommodate user needs for different distances and degrees of challenge by providing cutoffs for less experienced users on a system of loop trails, as follows:

Recommended Lengths Half Day Full Day

Easiest Trail                                    3.2 miles                 6.4 miles

Most Difficult Trail                          6.4 miles                 9.5 miles

c.  Bridges.  For minimum bridge widths and railing heights, see FSH 7709.56b, section 7.69, exhibit 01, Trail Bridge Design Criteria. 

d.  Intersections.  Approaches to intersections should have grades of 5 percent or less to allow for speed control.  Clear intersections to a diameter of twice the trail width.

e.  Marking Standards. Cross-country ski trails should be marked so that travelers unfamiliar with the trails can follow them during poor weather conditions, when there are with no tracks to follow and relatively poor lighting.  See the Sign and Poster Guidelines for the Forest Service (EM 7100-15) for guidance on marking trails.