LOCATION MULGON WY+COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Mollic Glossocryalfs
TYPICAL PEDON: Mulgon very stony loam in forestland. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; needles, bark, twigs, and grass leaves.
Oe--1 to 2 inches; decomposing needles, bark, twigs, and grass leaves.
A--2 to 5 inches; dark grayish brown (10YR 4/2) very stony loam, dark brown (7.5YR 3/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; many roots of all sizes; 20 percent gravel, 10 percent cobbles, 5 percent stones; moderately acid (pH 6.0); abrupt smooth boundary. (3 to 6 inches thick)
E--5 to 10 inches; brown (7.5YR 5/3) very stony fine sandy loam, dark brown (7.5YR 4/2) moist; weak thin platy structure parting to weak fine subangular blocky; soft, very friable, slightly sticky and slightly plastic; common roots of all sizes; 15 percent gravel, 10 percent cobbles, 10 percent stones; moderately acid (pH 6.0); gradual wavy boundary. (3 to 6 inches thick)
Bt/E--10 to 17 inches; grayish brown (10YR 5/2) very stony fine sandy loam, dark grayish brown (10YR 4/2) moist; moderate medium prismatic structure parting to moderate medium angular blocky; soft, very friable, slightly sticky and slightly plastic; common roots of all sizes; few faint clay films on faces of peds; 15 percent gravel, 10 percent cobbles, 10 percent stones; moderately acid (pH 6.0); gradual wavy boundary. (3 to 12 inches thick)
Bt1--17 to 25 inches; reddish brown (5YR 5/4) very stony sandy clay loam, reddish brown (5YR 4/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; common roots of all sizes; many prominent clay films on faces of peds; 25 percent gravel, 15 percent cobbles, 10 percent stones; moderately acid (pH 6.0); gradual wavy boundary. (6 to 16 inches thick)
Bt2--25 to 33 inches; reddish yellow (5YR 6/6) very stony sandy clay loam, yellowish red (5YR 5/6) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few roots of all sizes; common prominent clay films on vertical faces of peds; 25 percent gravel, 15 percent cobbles, 10 percent stones; moderately acid (pH 6.0); gradual wavy boundary. (4 to 8 inches thick)
C--33 to 60 inches; reddish yellow (5YR 6/6) very stony sandy loam, yellowish red (5YR 5/6) moist; massive; soft, very friable, slightly sticky and nonplastic; 25 percent gravel, 15 percent cobbles, 10 percent stones; moderately acid (pH 6.0).
TYPE LOCATION: Washakie County, Wyoming; located about 2,100 feet south and 600 feet east of the northwest corner of sec. 4, T. 42 N., R. 86 W.
RANGE IN CHARACTERISTICS:
Soil moisture: Udic moisture regime.
Depth to albic horizon: 3 to 6 inches from mineral surface
Depth to glossic horizon: 6 to 12 inches from mineral surface
Depth to argillic horizon: 10 to 24 inches from mineral surface
Depth to base of argillic horizon: 20 to 42 inches from mineral surface
Thickness of the Ochric epipedon: 3 to 6 inches
Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Rock fragments: 35 to 60 percent gravel, cobbles, stones,
or boulders
A horizon:
Hue: 5YR to 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3
Reaction: moderately acid or slightly acid
E horizon:
Hue: 2.5YR to 7.5YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 3 to 6
Texture: SL, L, or FSL modified by 35 to 60 percent rock fragments
Reaction: moderately acid or slightly acid
Bt/E or E/Bt horizon:
Hue: 2.5YR to 7.5YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 3 to 6
Texture: (E part)SL, L, or FSL modified by 35 to 60 percent rock fragments
(Bt part) SCL modified by 35 to 60 percent rock fragments
Reaction: moderately acid or slightly acid
Bt horizon:
Hue: 2.5YR to 7.5YR
Value: 4 to 6 dry, 2 to 5 moist
Chroma: 2 to 6
Texture: L, SCL, or CL modified by 35 to 60 percent rock fragments
Clay content: 18 to 35 percent
Reaction: moderately acid or slightly acid
C horizon:
Hue: 5YR or 7.5YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 6
Texture: SL, L, SCL, or CL modified by 15 to 60 percent cobbles or stones
Reaction: moderately acid or slightly acid
COMPETING SERIES: There are no competing series in this family
GEOGRAPHIC SETTING:
Parent material: colluvium or alluvium
Landform: mountains or alluvial fans along mountain fronts
Slopes: 5 to 65 percent
Elevation: 6,500 to 8,500 feet with elevations to 11,000 feet in Colorado
Mean annual temperature: 34 to 43 degrees F
Mean annual precipitation: 18 to 30 inches
Precipitation pattern: precipitation is relatively evenly distributed throughout the year
Frost-free period: 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Lucky Star series. The Lucky Star soils have a Bt horizon that begins greater than 24 inches deep.
DRAINAGE AND PERMEABILITY: Well drained, low to high runoff, moderate or moderately slow permeability.
USE AND VEGETATION: These soils are used for timber production, recreation, rangeland, and wildlife habitat. Native vegetation is ponderosa pine and Douglas-fir with an understory of pinegrass and sedge.
DISTRIBUTION AND EXTENT: The Big Horn Mountains of north-central Wyoming, and western Colorado; LRR E, MLRA 46, 47, and 48A; This series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Washakie county, Wyoming, 1976.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 15 to 31 inches. (Bt1 and Bt2 horizons)
Ochric epipedon: The zone from 2 to 5 inches. (A horizon)
Albic horizon: The zone from 5 to 10 inches. (E horizon)
Glossic horizon: The zone from 10 to 17 inches. (Bt/E horizon)
Argillic horizon: The zone from 17 to 33 inches (Bt1, Bt2 horizons)
Remarks:
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Percent base saturation for assignment to the mollic subgroup is estimated.
Glossic horizon is assumed to exist based on the presence of the Bt/E but cannot be confirmed since the description lacks percentages of Bt vs. E.
ADDITIONAL DATA: This soil formally classified as Mollic Cryoboralfs prior to the 1996 Keys. Classification according to the 1996 Keys was Glossic Cryoboralf, loamy-skeletal, mixed, superactive.
Taxonomic Version: Eighth Edition, 1998.