LOCATION WHITLASH MT
Established Series
Rev. DES-RJS-EMM
04/2014
WHITLASH SERIES
The Whitlash series consists of shallow, well drained soils that formed in colluvium and residuum derived from fine grained igneous rocks and noncalcareous sandstone and siltstone. These soils are on eroded fan remnants, mountain slopes, hillslopes, escarpments, structural benches, ridges, lahars and alluvial fans. Slopes are 4 to 70 percent. Mean annual precipitation is about 450 mm, and mean annual air temperature is about 5.5 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Haplustolls
TYPICAL PEDON: Whitlash gravelly loam, in rangeland (colors are for dry soil unless otherwise noted).
A1--0 to 10 cm; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine granular structure; soft, very friable, slightly sticky and slightly plastic; 20 percent gravel; neutral (pH 6.8); clear smooth boundary.
A2--10 to 23 cm; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure parting to moderate medium and fine granular; slightly hard, very friable, slightly sticky and slightly plastic; 20 percent gravel, 5 percent cobbles; neutral (pH 6.8); clear smooth boundary. (combined thickness of the A1 & A2 horizons - 18 to 25 cm)
Bw--23 to 40 cm; brown (10YR 5/3) very gravelly loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; 35 percent gravel, 15 percent cobbles; neutral (pH 7.0); abrupt smooth boundary. (15 to 25 cm thick)
R--40 cm; igneous bedrock.
TYPE LOCATION: Liberty County, Montana; 730 meters east and 550 meters north of the SW corner of sec. 13, T. 36 N., R. 4 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 3.5 to 8.0 degrees F.
Mollic epipedon thickness - 18 to 38 cm
Depth to a lithic contact - 25 to 50 cm
Note: The A2 and/or Bw horizons are not present in all pedons. Some pedons have a C horizon.
A1, A2 horizons
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3; dry or moist
Texture: loam, sandy clay loam, sandy loam or coarse sandy loam
Clay content: 5 to 27 percent
Rock fragments: 15 to 60 percent--15 to 40 percent gravel/channers, 0 to 30 percent cobbles, flagstones, or stones
Reaction: pH 6.1 to 7.4
Bw horizon
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam, sandy clay loam, sandy loam or coarse sandy loam
Clay content: 5 to 27 percent
Rock fragments: 35 to 80 percent--15 to 60 percent gravel/channers, 5 to 50 percent cobbles, flagstones, or stones
Reaction: pH 6.1 to 7.4
C horizon (where present)
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 or 3; dry or moist
Texture: sandy loam, coarse sandy loam, loamy sand or loamy coarse sand
Clay content: 5 to 15 percent
Rock fragments: 35 to 80 percent--15 to 60 percent gravel/channers, 5 to 50 percent cobbles, flagstones, or stones
Reaction: pH 6.1 to 7.4
COMPETING SERIES:
Castner (MT) - have secondary calcium carbonate accumulation
Catgulch (MT) - have a paralithic contact above a lithic contact
Celeste (CO) - do not have a cambic horizon
Cosnino (AZ) - dry in the moisture control section in
May and June
Duffymont (CO) - do not have a cambic horizon
Firo (NM) - dry in the moisture control section during April,
May, and June
Highpark (CO) - do not have a cambic horizon
Moonset (UT) - do not have a cambic horizon
Nivean (MT) - have a paralithic contact above a lithic contact
Paunsaugunt (UT) - do not have a cambic horizon
Vershal (MT) - are very shallow
Wuby (UT) - do not have a cambic horizon
GEOGRAPHIC SETTING:
Landform - eroded fan remnants, mountain slopes, hillslopes, escarpments, structural benches, ridges, lahars and alluvial fans
Elevation - 775 to 1,900 meters
Slope - 4 to 70 percent
Parent material - colluvium and residuum derived from fine grained igneous rocks and noncalcareous sandstone and siltstone
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 375 to 575 mm
Mean annual air temperature - 2.5 to 7.5 degrees C.
Frost-free period - 70 to 120 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Whitlash soils are used mainly for rangeland. The potential native vegetation is bluebunch wheatgrass, rough fescue, Idaho fescue, needleandthread, western wheatgrass, and shrubs. Some areas have an overstory of ponderosa pine, Douglas fir, or limber pine.
DISTRIBUTION AND EXTENT: Whitlash soils are in north central and western Montana. They are extensive. MLRAs - 43B, 44B, 44A, 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Toole County, Montana, 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 23 cm (A1, A2 horizons)
Cambic horizon - form 23 to 40 cm (Bw horizon)
Lithic contact at 40 cm (R horizon)
Particle-size control section - from 25 to 40 cm (part of Bw horizon).
Whitlash soils have a frigid temperature regime and an ustic moisture regime.
Additional Information: Soil interpretations records - MT1281, MT1282.
National Cooperative Soil Survey
U.S.A.