Trail Classes are general categories reflecting trail development scale, arranged along a continuum. The Trail Class identified for a National Forest System (NFS) trail prescribes its development scale, representing its intended design and management standards.1 Local deviations fromany Trail Class descriptor may be established based on trail-specific conditions, topography, or other factors, provided that the deviations do notundermine the general intent of the applicable Trail Class.
Identify the appropriate Trail Class for each National Forest System trail or trail segment based on the management intent in the applicable land
management plan, travel management direction, trail-specific decisions, and other related direction. Apply the Trail Class that most closely
matches the management intent for the trail or trail segment, which may or may not reflect the current condition of the trail.
Trail
Attributes
Tread&
Traffic Flow

Trail Class 1

Trail Class 2

Minimally Developed

Moderately Developed• Tread intermittent andoften indistinct• May require route finding• Tread continuous anddiscernible, but narrow andrough• Single lane with noallowances constructed
for passing• Single lane with minor
allowances constructed for
passing• Predominantly native
materials• Typically native materials

Trail Class 3
Developed

Trail Class 4

Trail Class 5

Highly Developed

Fully Developed• Tread continuous andobvious• Tread wide and relatively
smooth with few irregularities• Tread wide, firm, stable,
and generally uniform• Single lane, withallowances constructed
for passing where requiredby traffic volumes inareas with no reasonablepassing opportunities
available• Single lane, with allowances
constructed for passing
where required by traffic
volumes in areas withno reasonable passing
opportunities available• Single lane, with frequent
turnouts where traffic
volumes are low tomoderate• Native or imported
materials• Double lane where traffic
volumes are high and passing
is frequent• Native or imported materials• Double lane where traffic
volumes are moderate tohigh• Commonly hardened withasphalt or other imported
material• May be hardened
Obstacles• Obstacles common,
naturally occurring, often
substantial and intended
to provide increased
challenge• Narrow passages; brush,
steep grades, rocks andlogs present• Obstacles may becommon, substantial,
and intended to provide
increased challenge• Obstacles may becommon, but not
substantial or intended toprovide challenge• Blockages cleared to defineroute and protect resources• Vegetation cleared outsideof trailway• Obstacles infrequent andinsubstantial• Obstacles not present• Grades typically < 8%

• Vegetation cleared outside oftrailway• Vegetation may encroach
into trailway

33

10/16/2008

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

34

Trail
Attributes
ConstructedFeatures&
Trail Elements

Minimally Developed

Trail Class 1

Moderately Developed

Trail Class 2

Trail Class 3• Structures minimal tonon-existent• Structures of limited
size, scale, and quantity;
typically constructed ofnative materials• Structures may becommon and substantial;
constructed of imported ornative materials• Structures frequent andsubstantial; typicallyconstructed of imported
materials• Structures frequent orcontinuous; typicallyconstructed of imported
materials• Structures adequate toprotect trail infrastructure
and resources• Natural or constructed
fords• Constructed or natural fords• May include bridges,
boardwalks, curbs,
handrails, trailside
amenities, and similarfeatures• Drainage typicallyaccomplished without
structures• Natural fords• Typically no bridges• Natural fords• Bridges as needed forresource protection andappropriate accessSigns2• Route identification
signing limited tojunctions• Route markers present
when trail location is notevident• Destination signing,
unless required, generally
not present

TypicalRecreation
Environs&
Experience3• Route markers present
when trail location is notevident• Regulatory and resource
protection signing
infrequent• Destination signing typicallyinfrequent outside ofwilderness; generally notpresent in wilderness• Bridges as needed forresource protection andappropriate access• Route identification
signing at junctions
and as needed for user
reassurance• Route markers as needed
for user reassurance• Regulatory and resource
protection signing may becommon• Destination signing likely
outside of wilderness;
generally not present inwilderness• Information andinterpretive signing
generally not present• Information and interpretive
signing not common• Natural, unmodified• Natural, essentiallyunmodified• Natural, primarily
unmodified• ROS: Typically Primitive toRoaded Natural• ROS: Typically Primitive toRoaded Natural• WROS: Typically Primitive
to Semi-Primitive• WROS: Typically SemiPrimitive to Transition• ROS: Typically Primitive
to Roaded Natural• WROS: Typically Primitive
to Semi-Primitive• Information andinterpretive signs may
be present outside ofwilderness

Trail Class 4

Highly Developed• Bridges as needed forresource protection and userconvenience• Trailside amenities may bepresent

Trail Class 5

Fully Developed• Route identification signing atjunctions and as needed foruser reassurance• Route identification
signing at junctions andfor user reassurance• Route markers as needed foruser reassurance• Route markers as needed
for user reassurance• Regulatory and resource
protection signing common• Regulatory and resource
protection signingcommon• Destination signing common
outside of wilderness;
generally not present inwilderness• Information and interpretive
signs may be common
outside of wilderness• Accessibility information likely
displayed at trailhead• Destination signingcommon• Information andinterpretive signs common• Accessibility information
likely displayed attrailhead• May be modified• May be highly modified• ROS: Typically Semi-Primitive
to Rural• Commonly associatedwith visitor centers or
high-use recreation sites• WROS: Typically Portal orTransition• ROS: Typically Roaded
Natural to Urban• Generally not present inwilderness

1 For National Quality Standards for Trails, Potential Appropriateness of Trail Classes for Managed Uses, Design Parameters, and other related guidance, refer to FSM 2353, FSH 2309.18,

and other applicable agency references.
2 For standards and guidelines for the use of signs and posters along trails, refer to the Sign and Poster Guidelines for the Forest Service (EM-7100-15).
3 The Trail Class Matrix shows the combinations of Trail Class and Recreation Opportunity Spectrum (ROS) or Wilderness Recreation Opportunity Spectrum (WROS) settings that com-monly occur, although trails in all Trail Classes may and do occur in all settings. For guidance on the application of the ROS and WROS, refer to FSM 2310 and 2353 and FSH 2309.18.

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)• Regulatory and resource
protection signing
infrequent• Route identification signing
limited to junctions

DevelopedTrail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

USFS Trail Class Photo Examples
The following photos provide visual examples of typical Trail Class scenarios. Remember that Trail Classes are
general categories reflecting development scale, arranged along a continuum, with no hard and fast lines drawn
between the classes. Use the photos as visual aids to assist in consistent application of trail classification.

Trail Class 1

Trail Class 1: Tread—The tread is intermittent andindistinct.

Trail Class 1: Obstacles—Obstacles are common,
naturally occurring, and often substantial.

35

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 1: Constructed Features—Constructed features are minimal to nonexistent.

Trail Class 1: Signs—Route identification signing islimited to junctions. Route markers are present when
the trail location is not evident.

36

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 1: Typical Recreation Environment/Experience—The typical recreation
environment/experience is natural and unmodified.

37

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 2

Trail Class 2: Tread—The tread is continuous and discernible, but narrow and rough.

Trail Class 2: Obstacles—Obstacles may be commonand substantial. Blockages are cleared to define theroute and protect resources. Vegetation may encroach
into the trailway.

38

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 2: Constructed Features—Constructed features are of limited size, scale,and quantity.

39

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 2: Signs—Route identification signing is limited to junctions. Route markers are present when the
trail location is not evident.

Trail Class 2: Typical Recreation Environment/Experience—The typical recreation
environment/experience is natural and essentially unmodified.

40

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 3

Trail Class 3: Tread—The tread is continuous and obvious.

Trail Class 3: Obstacles—Obstacles may be common. Vegetation is cleared outsideof the trailway.

41

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 3: Constructed Features—Constructedfeatures such as walls, steps drainage, and raised trail,
may be common and substantial.

Trail Class 3: Signs—Route identification signing is present at junctions and as needed for user reassurance.
Destination signing is likely outside of wilderness areas.

42

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 3: Typical Recreation Environment/Experience—The recreation
environment/experience is natural and primarily unmodified.

43

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 4

Trail Class 4: Tread—The tread is wide and relatively smooth, with few irregularities.

Trail Class 4: Obstacles—Obstacles are infrequentand insubstantial. Vegetation is cleared outside of thetrailway.

44

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 4: Constructed Features—Constructed features are frequent and substantial.
Trailside amenities may be present.

45

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 4: Signs—A wide variety of signing is likely present. Informational signs are likely and interpretive
signs are possible.

Trail Class 4: Typical Recreation Environment/Experience—The recreation environment/experience may be modified.

46

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 5

Trail Class 5: Tread—The tread is wide, firm, stable,
and generally uniform. Trails are commonly hardenedwith asphalt or other imported material.

Trail Class 5: Obstacles—Obstacles are not present.
Grades are typically less than 8 percent.

Trail Class 5: Constructed Features—Constructed features are frequent or continuous. Structures may include
bridges, boardwalks, curbs, handrails, trailside amenities, and similar features.

47

Trail Class Matrix (FSH 2353, Section 14.2, Exhibit 01)

Trail Class 5: Signs—A wide variety of signing is present. Informational and interpretive signs are common.

Trail Class 5: Typical Recreation Environment/Experience—The recreation environment/experience may be highly modified.

48

Hiker/Pedestrian (FSH 2309.18, Section 23.11, Exhibit 01)
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 intent.1 Local deviations from any Design Parameter may beestablished 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
HIKER/PEDESTRIAN
DesignTread
Width

DesignSurface3

Trail Class 1

Trail Class 2

Wilderness(Single Lane)0″ – 12″6″ – 18″

Non-Wilderness(Single Lane)0″ – 12″

Non-Wilderness(Double Lane)
Structures(Minimum Width)Type

Trail Class 32

Trail Class 42

Trail Class 52
Not applicable

12″ – 24″

18″ – 24″

Exception: may be
36″ – 48″ at steep sideslopesException: may be
36″ – 48″ at steep sideslopes6″ – 18″18″ – 36″

24″ – 60″

36″ – 72″

36″

36″

36″ – 60″

48″ – 72″

72″ – 120″

18″

18″

18″

36″

36″

Native with improved
sections of borrow
or imported material,
and routine grading

Likely imported
material, and routine
grading

Native, ungradedMay becontinuously roughNative, limited
grading
May be continuously
roughNative, with some
onsite borrow orimported material
where needed forstabilization andoccasional grading

Minor roughness

Uniform, firm, andstableIntermittently rough
≤ 6″

≤ 3″

May be common andcontinuous

May be common, notcontinuous

24″

14″

10″

8″

Target Grade

5% – 25%

5% – 18%

3% – 12%2% – 10%2% – 5%

Short Pitch
Maximum

40%

35%

25%

15%

5%
FSTAG: 5% – 12%2

20% – 40% of trail

20% – 30% of trail

10% – 20% of trail

5% – 20% of trail

0% – 5% of trail

Obstacles(Maximum Height)

DesignGrade3

Maximum Pitch
Density≤ 3″

No protrusions≤ 24″
Likely common andcontinuous

Protrusions

Uncommon, notcontinuous
No obstacles

49
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Trail Design Parameters

Trail Design Parameters

50

Designed Use
HIKER/PEDESTRIAN

Trail Class 1

Trail Class 2

Trail Class 32

Trail Class 42

Trail Class 52

DesignCross
SlopeTarget Cross Slope

Natural side slope

5% – 20%

5% – 10%3% – 7%2% – 3%(or crowned)

Maximum Cross
Slope

Natural side slope

25%

15%

10%

3%

DesignClearing

Height6′

6′ – 7′

7′ – 8′8′ – 10′8′ – 10′36″ – 60″

48″ – 72″

60″ – 72″

Width

Shoulder Clearance

DesignTurn

Radius≥ 24″

24″ – 48″

Some vegetation
may encroach into
clearing area

Some light vegetation
may encroach into
clearing area

3″ – 6″6″ – 12″12″ – 18″

12″ – 18″

12″ – 24″

No minimum

2′ – 3′3′ – 6′4′ – 8′

6′ – 8′1 For definitions of Design Parameter attributes (for example, Design Tread Width and Short Pitch Maximum) see FSH 2309.18, Section 05.
2 Trail Classes 3, 4, and 5, in particular, have the potential to provide accessible passage. If assessing or designing trails for accessibility, refer to the Forest Service Trail Accessibility

Guidelines (FSTAG) for more specific technical provisions and tolerances (FSM 2350).
3 The determination of trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, andother factors contributing to surface stability and overall sustainability of the trail.

Trail Design ParametersPack and Saddle (FSH 2309.18, Section 23.12, Exhibit 01)
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 intent.1 Local deviations from any Design Parameter may beestablished 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
PACK AND SADDLE
DesignTread
Width

Wilderness(Single Lane)

Non-Wilderness(Single Lane)

Trail Class 1
Typically notdesigned or
actively managed
for equestrians,
although use may
be allowed

Trail Class 2

Trail Class 3

Trail Class 4

Trail Class 5
Typically notdesigned or
actively managed
for equestrians,
although use may
be allowed

12″ – 18″18″ – 24″

24″

May be up to 48″ along
steep side slopes

May be up to 48″ along
steep side slopes

May be up to 48″ along
steep side slopes

48″ – 60″ or greater
along precipices

48″ – 60″ or greater
along precipices

48″ – 60″ or greater
along precipices

12″ – 24″
May be up to 48″ along
steep side slopes

18″ – 48″48″ – 60″ or greater
along precipices

24″ – 96″
48″ – 60″ or greater
along precipices

48″ – 60″ or greater
along precipices

DesignSurface2

Non-Wilderness(Double Lane)

60″

60″ – 84″

84″ – 120″

Structures(Minimum Width)

Other than bridges: 36″

Other than bridges: 36″

Other than bridges: 36″

Bridges without
handrails: 60″

Bridges without
handrails: 60″

Bridges without
handrails: 60″

Bridges with handrails:
84″ clear width

Bridges with handrails:
84″ clear width

Bridges with handrails:
84″ clear width

Native, with limited
grading

Native, with some onsite
borrow or imported
material where needed
for stabilization andoccasional grading

Native, with improved
sections of borrow orimported material androutine gradingType

May be frequently
roughIntermittently roughProtrusions≤ 6″
May be common andcontinuous

Obstacles(Maximum Height)

12″

≤ 3″
May be common, notcontinuous
6″

Minor roughness≤ 3″
Uncommon, notcontinuous
3″51
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Trail Design Parameters

Trail Design Parameters

52

Designed Use
PACK AND SADDLE
DesignGrade2

Target Grade
Short Pitch
Maximum
Maximum Pitch
Density

Trail Class 1
Typically notdesigned or
actively managed
for equestrians,
although use may
be allowed

Trail Class 2

Trail Class 3

Trail Class 4

Trail Class 55% – 20%

3% – 12%2% – 10%

30%

20%

15%

15% – 20% of trail

5% – 15% of trail

5% – 10% of trail

Typically notdesigned or
actively managed
for equestrians,
although use may
be allowed

5% – 10%3% – 5%0% – 5%

DesignCross
SlopeTarget Cross
Slope
Maximum Cross
Slope

10%

8%

5%

DesignClearing

Height8′ – 10′10′

10′ – 12′72″

72″ – 96″

96″

Width

Some light vegetation
may encroach into
clearing area
ShoulderClearance

DesignTurn

Radius6″ – 12″12″ – 18″

12″ – 18″

Pack clearance:
36″ x 36″

Pack clearance:
36″ x 36″

Pack clearance:
36″ x 36″

4′ – 5′5′ – 8′

6′ – 10′

1 For definitions of Design Parameter attributes (for example, Design Tread Width and Short Pitch Maximum) see FSH 2309.18, Section 05.
2 The determination of trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, andother factors contributing to surface stability and overall sustainability of the trail.

Trail Design ParametersBicycle (FSH 2309.18, Section 23.13, Exhibit 01)
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 intent.1 Local deviations from any Design Parameter may beestablished 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
BICYCLE

Trail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

DesignTread
WidthSingle Lane6″ – 12″12″ – 24″

18″ – 36″

24″ – 48″

36″ – 60″

Double Lane

36″ – 48″

36″ – 48″

36″ – 48″48″ – 84″

72″ – 120″

18″

18″

36″

48″

60″

DesignSurface2

Type

Native, with some onsite
borrow or imported
material where needed
for stabilization andoccasional grading

Native, with improved
sections of borrow orimported materials androutine grading

Structures(Minimum Width)

Native, ungradedMay becontinuously roughSections of soft or
unstable tread on
grades < 5% may
be common andcontinuous

Sections of soft or
unstable tread on
grades < 5% may becommonIntermittently roughStable, with minor
roughness

Uniform, firm, andstableSections of soft or
unstable tread on grades< 5% may be present,
but not common

≤ 6″

≤ 3″

May be common andcontinuous

May be common, but
not continuous

24″

12″

10″

8″

Target Grade

5% – 20%

5% – 12%3% – 10%2% – 8%2% – 5%

Short Pitch
Maximum

30%

25%

15%

10%

8%

50% on downhill
segments only

≤ 3″

No protrusions≤ 24″

Obstacles(Maximum Height)

DesignCross
Slope

May be continuously
roughLikely imported
material androutine grading

Likely common andcontinuous

Protrusions

DesignGrade2Native, with limited
grading

Trail Class 5

Uncommon and notcontinuous
No obstacles

35% on downhill
segments only

Maximum Pitch
Density

20% – 30% of trail

10% – 30% of trail

10% – 20% of trail

5% – 10% of trail

0% – 5% of trail

Target Cross
Slope

5% – 10%5% – 8%3% – 8%3% – 5%2% – 3%

10%

10%

8%

5%

5%

53

Maximum Cross
Slope

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Trail Design Parameters

Trail Design Parameters

54

Designed Use
BICYCLE
DesignClearing

DesignTurn

HeightTrail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

Trail Class 5

6′

6′ – 8′8′

8′ – 9′8 ′ – 9′60″ – 72″

72″ – 96″

72″ – 96″

24″ – 36″

36″ – 48″

Some vegetation
may encroach into
clearing area

Some light vegetation
may encroach into
clearing area

ShoulderClearance

0″ – 12″6″ – 12″6″ – 12″6″ – 18″

12″ – 18″

Radius2′ – 3′3′ – 6′4′ – 8′8′ – 10′8′ – 12′Width

1 For definitions of Design Parameter attributes (for example, Design Tread Width and Short Pitch Maximum) see FSH 2309.18, Section 05.
2 The determination of trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, andother factors contributing to surface stability and overall sustainability of the trail.

Trail Design Parameters

Motorcycle (FSH 2309.18, Section 23.21, Exhibit 01)
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 intent.1 Local deviations from any Design Parameter may beestablished 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
MOTORCYCLE
DesignTread
Width
DesignSurface2

Single Lane
Double Lane
Structures(Minimum Width)Type

Trail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

Typically not designed
or actively managed
for motorcycles,
although use may beallowed8″ – 24″

18″ – 36″

24″ – 48″48″

48″ – 60″60″ – 72″

36″

48″

48″

Native, with limited
grading
May be continuously
roughSections of soft or
unstable tread on
grades < 5% may
be common andcontinuous

Protrusions

Obstacles(Maximum Height)

DesignGrade2Native, with some onsite
borrow or imported
material where needed
for stabilization andoccasional grading

Native, with imported
materials for tread
stabilization likely androutine grading

Intermittently roughSections of soft tread notcommonSections of soft or
unstable tread on
grades < 5% may bepresent

≤ 6″

≤ 3″

May be common andcontinuous

May be common, but
not continuous

18″

12″

May be common orplaced for increased
challenge

Common and left forincreased challenge

Minor roughness≤ 3″
Uncommon and notcontinuous
3″
UncommonTarget Grade

10% – 25%

5% – 20%

3% – 10%

Short Pitch
Maximum

40%

25%

15%

20% – 40% of trail

15% – 30% of trail

10% – 20% of trail

Maximum Pitch
Density

Trail Class 5
Typically notdesigned or
actively managed
for motorcycles,
although use may
be allowed

55
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Trail Design Parameters

Trail Design Parameters

56

Designed Use
MOTORCYCLE
DesignCross
Slope
DesignClearing

DesignTurn

Target Cross
Slope
Maximum Cross
Slope
HeightWidth(On steep side
hills, increase
clearing on uphillside by 6″ – 12″)Trail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

Typically not designed
or actively managed
for motorcycles,
although use may beallowed5% – 10%5% – 8%3% – 5%

15%

10%

10%

6′ – 7′

6′ – 8′8′ – 10′36″ – 48″48″ – 60″60″ – 72″

Trail Class 5
Typically notdesigned or
actively managed
for motorcycles,
although use may
be allowed

Some light vegetation
may encroach into
clearing area

ShoulderClearance

6″ – 12″12″ – 18″

12″ – 24″

Radius3′ – 4′4′ – 6′5′ – 8′1 For definitions of Design Parameter attributes (for example, Design Tread Width and Short Pitch Maximum) see FSH 2309.18, Section 05.
2 The determination of trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, andother factors contributing to surface stability and overall sustainability of the trail.

Trail Design Parameters

All-Terrain Vehicle (FSH 2309.18, Section 23.22, Exhibit 01)
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 intent.1 Local deviations from any Design Parameter may beestablished 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
ALL-TERRAIN VEHICLE
DesignTread
WidthSingle Lane

DesignSurface2

Type

Double Lane
Structures(Minimum Width)

Trail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

Trail Class 5

Typically not designed
or actively managed
for ATVs, although
use may be allowed

48″ – 60″

60″

60″ – 72″

96″

96″ – 108″96″ – 120″

60″

60″

60″

Typically notdesigned or actively
managed for ATVs,
although use may
be allowed

Native, with limited
grading
May be continuously
roughSections of soft or
unstable tread on
grades < 5% may
be common andcontinuous

Protrusions

Obstacles(Maximum Height)

DesignGrade2Native, with some onsite
borrow or imported
material where needed
for stabilization andoccasional grading

Native, with imported
materials for tread
stabilization likely androutine grading

Intermittently roughSections of soft tread
uncommon

Sections of soft or
unstable tread on
grades < 5% may bepresent

≤ 6″

≤ 3″

May be common andcontinuous

May be common, but
not continuous

12″

6″

May be common orplaced for increased
challenge

May be common
and left for increased
challenge

Minor roughness≤ 3″
Uncommon and notcontinuous
3″
UncommonTarget Grade

10% – 25%

5% – 15%3% – 10%

Short Pitch
Maximum

35%

25%

15%

20% – 40% of trail

15% – 30% of trail

10% – 20% of trail

Maximum Pitch
Density57
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Trail Design Parameters

58

Designed Use
ALL-TERRAIN VEHICLE

Trail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

Trail Class 5

Typically not designed
or actively managed
for ATVs, although
use may be allowed

5% – 10%3% – 8%3% – 5%

15%

10%

8%

Typically notdesigned or actively
managed for ATVs,
although use may
be allowed

DesignCross
SlopeTarget Cross
Slope

DesignClearing

Height6′ – 7′

6′ – 8′8′ – 10′Width(On steep side
hills, increase
clearing on uphillside by 6″ – 12″)60″

60″ – 72″

72″ – 96″

DesignTurn

Maximum Cross
Slope

Some light vegetation
may encroach into
clearing area

ShoulderClearance

0″ – 6″6″ – 12″12″ – 18″

Radius6′ – 8′8′ – 10′8′ – 12′

1 For definitions of Design Parameter attributes (for example, Design Tread Width and Short Pitch Maximum) see FSH 2309.18, Section 05.
2 The determination of trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, andother factors contributing to surface stability and overall sustainability of the trail.

Trail Design Parameters

Four-Wheel Drive Vehicle > 50″ (FSH 2309.18, Section 23.23, Exhibit 01)
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 intent.1 Local deviations from any Design Parameter may beestablished 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
FOUR-WHEEL DRIVE VEHICLE > 50″
DesignTread
Width
DesignSurface2

Single Lane
Double Lane
Structures(Minimum Width)Type

Trail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

Trail Class 5

Typically notdesigned or actively
managed for 4WD
vehicles > 50″,although use may beallowed72″ – 84″

72″ – 96″96″ – 120″

16′

16′

16′

96″

96″

96″

Native, with limited
grading

Native, with someon-site borrow orimported material
where needed forstabilization andoccasional grading

Native, with imported
materials for tread
stabilization likely
and routine grading

Typically notdesigned or actively
managed for 4WD
vehicles > 50″,although use may
be allowed

May becontinuously roughSections of soft or
unstable tread on
grades < 5% may
be common andcontinuous

Protrusions≤ 12″
May be common
and continuous

Obstacles(Maximum Height)

DesignGrade2

Target Grade

Intermittently roughSections of soft or
unstable tread on
grades < 5% may bepresent≤ 8″
May be common
and continuous

36″

24″

May be common
or placed forincreasedchallenge

Common and left forincreased challenge

10% – 21%5% – 18%

Minor roughness
Sections of soft tread
uncommon≤ 4″
May be common andcontinuous
12″
Uncommon

5% – 12%

Short Pitch Maximum

25%

20%

15%

Maximum Pitch Density

20% – 30% of trail

10% – 20% of trail

5% – 10% of trail

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Trail Design Parameters

Trail Design Parameters

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Designed Use
FOUR-WHEEL DRIVE VEHICLE > 50″
DesignCross
Slope
DesignClearing

Target Cross Slope
Maximum Cross Slope
HeightWidth

Trail Class 1

Trail Class 2

Trail Class 3

Trail Class 4

Trail Class 5

Typically notdesigned or actively
managed for 4WD
vehicles > 50″,although use may beallowed8% – 15%5% – 12%5% – 8%

15%

12%

8%

Typically notdesigned or actively
managed for 4WD
vehicles > 50″,although use may
be allowed

6′ – 8′

6′ – 8′8′ – 10′72″ – 84″

72″ – 96″96″ – 144″

Some light
vegetation may
encroach into
clearing area

DesignTurn

Shoulder Clearance

0″ – 6″6″ – 12″12″ – 18″

Radius10′ – 15′15′ – 20′

20′ – 30′

1 For definitions of Design Parameter attributes (for example, Design Tread Width and Short Pitch Maximum) see FSH 2309.18, Section 05.
2 The determination of trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, andother factors contributing to surface stability and overall sustainability of the trail.

Trail Design Parameters