LOCATION LILSHEEP MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Torriorthentic Haplustolls
TYPICAL PEDON: Lilsheep gravelly loam, in rangeland. (Colors are for dry soil unless otherwise noted)
A--0 to 7 inches; brown (10YR 4/3) gravelly loam, dark brown (10YR 3/3) moist; weak medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; 25 percent rounded gravel fragments; slightly alkaline (pH 7.8); clear smooth boundary. (7 to 9 inches thick)
Bk1--7 to 12 inches; light yellowish brown (2.5Y 6/4) very gravelly loam, olive brown (2.5Y 4/4) moist; weak coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common fine and very fine pores; 40 percent rounded gravel fragments; common medium masses of lime around gravel fragments; violently effervescent; strongly alkaline (pH 8.8); clear wavy boundary.
Bk2--12 to 23 inches; light yellowish brown (2.5Y 6/4) very gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common fine and very fine roots; common fine and very fine pores; 50 percent rounded gravel fragments; common medium masses of lime around gravel fragments; violently effervescent; strongly alkaline (pH 8.8); gradual smooth boundary. (Combined Bk horizons 10 to 30 inches thick)
BC--23 to 43 inches; light yellowish brown (2.5Y 6/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; 55 percent rounded gravel fragments; few fine masses of lime around gravel fragments; strongly effervescent; moderately alkaline (pH 8.4); gradual smooth boundary.
Cr--43 to 60 inches; light gray (2.5Y 7/2) semiconsolidated sandstone, grayish brown (2.5Y 5/2) moist.
TYPE LOCATION: Custer County, Montana; 1,300 feet south and 700 feet west of the NE corner of sec. 26, T. 12 N., R. 45 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 43 to 46 degrees.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 9 inches.
Depth to paralithic contact - 40 to 60 inches.
Depth to Bk horizon:- 7 to 9 inches.
A horizon - Hue: 10YR or 2.5Y
Chroma: 2 or 3
Clay content: 18 to 27 percent
Rock fragments: 15 to 60 percent--0 to 55 percent gravel; 0 to 5 percent cobbles
Reaction: pH 6.6 to 7.8
Bk horizons - Hue: 10YR or 2.5Y
Value: 4 or 5 moist; 6 or 7 dry
Chroma: 2, 3, 4 or 6
Texture: loam, sandy loam or sandy clay loam
Clay content: 15 to 27 percent
Rock fragments: 35 to 60 percent--35 to 55 percent gravel; 0 to 5 percent cobbles
Calcium carbonate equivalent: 15 to 30 percent
Reaction: pH 7.9 to 9.0
BC horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 moist, 5 or 6 dry
Chroma: 2, 3, or 4
Texture: loam, sandy loam or sandy clay loam
Clay content: 15 to 27 percent
Rock fragments: 35 to 60 percent--35 to 55 percent gravel; 0 to 5 percent cobbles
Calcium carbonate equivalent: 8 to 15 percent
Reaction: 7.9 to 9.0
COMPETING SERIES:
Mergel - lacks bedrock between depths of 40 and 60 inches.
Redthyane - lacks bedrock between depths of 40 and 60 inches; does not have a calcic horizon; occurs at elevations of 6,500 to 7,000 feet.
Shibah - lacks bedrock between depths of 40 and 60 inches.
GEOGRAPHIC SETTING:
Landform - sedimentary plains, hills, relict stream terraces.
Elevation - 2,200 to 3,600 feet.
Slope- 4 to 45 percent.
Parent material - alluvium and colluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 100 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cabbart, Cambeth, Lonna and Floweree soils. All these soils lack rock fragments in the soil profile. Cabbart and Cambeth soils lack a mollic epipedon. In addition, Cabbart soils have soft bedrock at depths of 10 to 20 inches. Cabbart soils are on summits and shoulder slopes and Cambeth soils are on shoulder and backslopes. Lonna and Floweree soils occur on toeslopes and swales and lack soft bedrock between depths of 40 and 60 inches.
DRAINAGE AND PERMEABILITY: Well drained. Moderate permeability. Runoff is very low to high depending on slope.
USE AND VEGETATION: Lilsheep soils are used mainly as rangeland. A few small areas are used as cropland when in complex with other soils. Potential native vegetation is mainly bluebunch wheatgrass, needleandthread, little bluestem, blue grama, threadleaf sedge, plains muly, and fringed sagewort.
DISTRIBUTION AND EXTENT: Lilsheep soils are of small extent in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Custer County, Montana, 1995.
REMARKS: Soil interpretation record: MT0739.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 7 inches ( A horizon); calcic horizon - the zone from 7 to 23 inches (Bk1 and Bk2 horizons); paralithic contact - at 43 inches (Cr horizon); particle-size control section - the zone from 10 to 40 inches (Bk1, Bk2 and BC horizons).