2011-04-08_REVISION - M1983011 ‎(6)‎

• Permit No: M1983011
• IBM Index Class Name: REVISION
• Doc Date: 4/8/2011
• Doc Name: Conversion application ‎(CN-01)‎ to a 112
• From: Mt. Elbert Mining Co., LLC
• To: DRMS
• Type & Sequence: CN1
• Email Name: DMC
• Media Type: D
• Archive: No

Northern San Isabel and Western Pike National Forests, Colorado
Wildlife management considerations: This map
unit provides shelter and limited food during
summer through fall months. Thinning or
creating small openings in the overstory canopy
cover can stimulate understory productivity.
Other management considerations:
Management activities are limited by steep slopes
and erosion hazard. Some areas of this map unit
occur in generally remote areas which have had
relatively little disturbance other than fire. These
undisturbed areas can contain old growth trees.
Acid precipitation buffering capacity. low.
Map Unit: 691G-Leighcan - Howardsville
families complex, till substratum, 40 to 60 percent
south slopes.
Ecological Land Unit: 691 G-lodgepole pine,
subalpine fir, and Engelmann spruce on
subalpine, south facing lateral moraines.
MAP UNIT SETTINGS
Location: glaciated areas where igneous and
metamorphic rocks predominate.
Landform: lateral moraines.
Parent material: glacial till.
Geologic symbol: Qd.
Elevation range: 10,000 to 11,600 feet.
Aspect. south.
Climatic zone: subalpine.
Mean annual precipitation: 20 to 40 inches.
Mean annual air temperature: 341F. to 400F.
Average annual snowfall. 200 to 400 inches.
COMPOSITION
50 percent Leighcan and similar soils.
40 percent Howardsville and-similar soils.
Contrasting inclusions
10 percent rubbly glacial debris.
TYPICAL PROFILES:
Leighcan
Surface covering layer:
2.5 to 0 inches - conifer litter and duff.
Surface layer(s):
0 to 1 inches - very dark grayish brown, very
stony loam.
Subsurface layer(s):
1 to 7 inches - brown, very stony sandy loam.
7 to 12 inches - brown, extremely cobbly sandy
loam.
Subsoil layer(s):
12 to 32 inches - dark yellowish brown,
extremely cobbly sandy loam.
32 to 50 inches - yellowish brown, extremely
stony sandy loam.
Substratum layer(s):
50 to 65 inches - light olive brown, extremely
stony loamy sand.
Howardsville
Surface covering layer:
1 to 0 inches - conifer litter.
Surface layer(s):
0 to 2 inches - pale brown, very stony sandy
loam.
Subsurface layer(s):
2 to 13 inches - very pale brown, very stony
loamy sand.
Subsoil layer(s):
13 to 24 inches - light yellowish brown,
extremely stony loamy sand.
Substratum layer(s):
24 to 60 inches - brownish yellow, extremely
stony loamy sand.
SOIL PROPERTIES AND QUALITIES
Leighcan
Effective rooting depth: greater than 60 inches.
Drainage class: somewhat excessively.
Depth to seasonal high water table: greater
than 6 feet.
Available water capacity: very low to low.
Permeability. moderately rapid.
Runoff.• rapid.
Howardsville
Effective rooting depth: greater than 60 inches.
Drainage class: excessively.
Depth to seasonal high water table: greater
than 6 feet.
Available water capacity: very low.
Permeability. rapid.
Runoff.• medium.
VEGETATION
Potential natural communities:
Leighcan: lodgepole pine/Rocky Mountain
whortleberry (PicoNamy) below 10,500 feet and
subalpine fir-Engelmann spruce/Rocky
Mountain whortleberry (Abla-PienlNamy)
typical site, and subalpine fir-Engelmann
spruce/grouse whortleberry (Abla-Pienl/Juco)
dry site.
Howardsville: lodgepole pine/Rocky Mountain
whortleberry (PicoNamy) below 10,000 feet and
subalpine fir-Engelmann spruce/Rocky
Mountain whortleberry (Abla-PienlNamy)
below 11,000 feet and subalpine fir-Engelmann
spruce/grouse whortleberry (Abla-PienlNamc)
above 11,000 feet.
Seral stages: dominated with lodgepole pine.
Present vegetation: dominated by plants of the
respective potential natural communities.
Page 93 DRAFT 3/21/2011