LOCATION STUBBS WY+MT
Established Series
Rev. PSD-JJU-EMM
12/2022
STUBBS SERIES
The Stubbs series consists of moderately deep, well drained soils that formed in slope alluvium or colluvium over material weathered from sedimentary rock. Stubbs soils are on hills and mountains. Slopes are 2 to 25 percent. The mean annual precipitation is about 20 inches, and the mean air annual temperature is about 38 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Pachic Argicryolls
TYPICAL PEDON: Stubbs loam, rangeland (colors are for dry soil unless otherwise stated).
A--0 to 6 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; strong fine granular structure; soft, very friable, moderately sticky and slightly plastic; neutral (pH 6.8); clear smooth boundary. (4 to 8 inches thick)
AB--6 to 16 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak medium prismatic structure parting to moderate medium subangular blocky; slightly hard, very friable, moderately sticky and moderately plastic; neutral (pH 7.2); clear smooth boundary. (8 to 12 inches thick)
Bt1--16 to 20 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine prismatic structure parting to moderate fine subangular blocky; very hard, very friable, moderately sticky and moderately plastic; continuous faint clay films on faces of peds and in root channels; neutral (pH 7.2); gradual wavy boundary.
Bt2--20 to 30 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; moderate fine prismatic structure parting to moderate fine subangular blocky; very hard, very friable, moderately sticky and moderately plastic; continuous faint clay films on faces of peds and in root channels; slightly alkaline (pH 7.4); gradual wavy boundary. (combined thickness of the Bt1, Bt2 horizons - 6 to 24 inches)
Btk--30 to 34 inches; light yellowish brown (2.5Y 6/3) clay loam, light olive brown (2.5Y 5/3) moist; weak medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common faint clay films on faces of peds and in root channels; common soft masses of calcium carbonate; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (3 to 19 inches thick)
Cr--34 to 60 inches; weakly calcareous, soft shale and siltstone.
TYPE LOCATION: Johnson County, Wyoming; NW1/4, NW1/4, sec. 34, T. 45N, R. 84W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 38 to 43 degrees F.
Thickness of the mollic epipedon - 16 to 32 inches
Depth to secondary calcium carbonate accumulation - 15 to 36 inches
Depth to paralithic contact - 20 to 40 inches
Note: Some pedons may have a BCk or C horizon.
A, AB horizons
Hue: 2.5Y or 10YR; dry or moist
Value: 3 or 5 dry; 2 or 3 moist
Chroma: 1 or 2; dry or moist
Rock fragments: 0 to 15 percent gravel or channers
Reaction: neutral or slightly alkaline
Bt1, Bt2 horizons
Hue: 2.5Y, 10YR or 7.5YR; dry or moist
Value: 3 or 6 dry; 2 or 4 moist
Chroma: 2 to 4; dry or moist
Texture: loam or clay loam
Clay content: 25 to 35 percent clay
Rock fragments: 0 to 15 percent gravel or channers
Reaction: neutral or slightly alkaline
Btk horizon
Hue: 2.5Y, 10YR or 7.5YR; dry or moist
Value: 5 or 7 dry; and 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: loam or clay loam
Clay content: 18 to 35 percent clay
Calcium carbonate equivalent: 1 to 15 percent
Rock fragments: 0 to 15 percent total; 0 to 15 percent gravel or channers, 0 to 5 percent cobbles or stones
Reaction: slightly or moderately alkaline
COMPETING SERIES:
Bachus (WY) - are moderately deep to a lithic contact
Bavdark (MT) - are very deep
Benteen (MT) - are moderately deep to a lithic contact
Brushtop (ID) - are deep to a paralithic contact
Clayburn (UT) - are very deep
Croydon (UT) - are deep to a lithic contact
Crystalbutte (ID) - are very deep
Davtone (CO) - are very deep
Dehana (ID) - are very deep
Demast (ID) - are deep to a lithic contact
Dranburn (ID) - are very deep
Dranyon (ID) - are deep or very deep
Echemoor (WY) - do not have secondary calcium carbonate accumulation
Hagenbarth (ID) - are deep or very deep
Hoopgobel (ID) - have a xeric soil moisture regime
Lostminer (UT) - have an udic soil moisture regime
Millerlake (WY) - are very deep
Odark (MT) - are very deep
Senchert (UT) - are moderately deep to a lithic contact
Southmount (ID) - are very deep
Poodle (NV) - have a xeric soil moisture regime
Thulepah (NV) - are very deep
Vadnais (ID) - are moderately deep to a lithic contact
Winu (NV) - are moderately deep to a lithic contact
GEOGRAPHIC SETTING:
Landform - hills and mountains
Elevation - 5,700 to 9,000 feet
Slope - 2 to 25 percent
Parent material - slope alluvium or colluvium over material weathered from sedimentary rock
Mean annual precipitation - 17 to 24 inches
Mean annual air temperature - 35 to 41 degrees F.
Frost-free period - less than 80 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used for range, recreation, and wildlife habitat. Native vegetation is big sagebrush, Idaho fescue, Columbia needlegrass, King fescue, silvery lupine, and thickspike wheatgrass.
DISTRIBUTION AND EXTENT: Big Horn Mountains of north-central Wyoming and Central Rocky Mountains in Montana. The series is of moderate extent. MLRAs - 43B, 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Johnson County (Southern Part Area), Wyoming; 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 20 inches (A, AB, Bt1 horizons)
Argillic horizon - from 16 to 34 inches (Bt1, Bt2, Btk horizons)
Secondary calcium carbonate accumulation - from 30 to 34 inches (Btk horizon)
Paralithic contact - at 34 inches (Cr horizon)
Particle size control section - from 16 to 34 inches (Bt1, Bt2, Btk horizons)
Stubbs soils have a cryic temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.