LOCATION CLEARCREEK MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, frigid Oxyaquic Xerofluvents
TYPICAL PEDON: Clearcreek silt loam, 0 to 2 percent slopes, in pasture. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; light brownish gray (2.5Y 6/2) silt loam, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine and coarse roots and common medium roots; few fine interstitial and tubular pores; slightly alkaline (pH 7.6); clear smooth boundary. (4 to 7 inches thick)
C1--6 to 16 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; massive; distinct discontinuous bedding planes; slightly hard, friable, slightly sticky and slightly plastic; many fine roots and few medium and coarse roots; few fine tubular pores; slightly alkaline (pH 7.6); clear smooth boundary. (8 to 12 inches thick)
C2--16 to 35 inches; light gray (2.5Y 7/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; weak discontinuous bedding planes; slightly hard, friable, sticky and slightly plastic; common fine roots and few medium roots; common tubular pores; slightly alkaline (pH 7.8); gradual smooth boundary. (15 to 25 inches thick)
C3--35 to 60 inches; light gray (2.5Y 7/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; few fine and medium roots; few fine pores; moderately alkaline (pH 8.0).
TYPE LOCATION: Sanders County, Montana; 3,230 feet south and 300 feet east of the northwest corner of sec. 29, T. 20 N., R. 22 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 43 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to seasonal high water table - 42 to 60 inches.
These soils have an erratic carbon distribution to 1.25 meters. The homogeneous parent materials do not produce visual stratification typical for most fluvents.
A horizon - Hue: 2.5Y or 10YR
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3
Clay content: 10 to 27 percent
Reaction: pH 6.6 to 7.8
C1 horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Clay content: 10 to 27 percent
Reaction: pH 6.6 to 7.8
C2 and C3 horizons - Hue: 2.5Y or 10YR
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture, less than 2 mm: silty clay loam or silt loam
Clay content: 18 to 35 percent
Reaction: pH 7.4 to 8.4
These horizons may contain high chroma relic mottles.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - low stream terraces and flood plains in intermountain valleys.
Elevation - 2,500 to 3,000 feet.
Slope- 0 to 2 percent.
Parent material - silty alluvium.
Climate - long, cold winters; moist springs and falls; hot, dry summers.
Mean annual precipitation - 10 to 14 inches, much of which falls as snow and spring rain.
Mean annual temperature - 41 to 45 degrees.
Frost-free period - 100 to 120 days.
DRAINAGE AND PERMEABILITY: Moderately well drained; moderately slow permeability.
USE AND VEGETATION: Clearcreek soils are used as rangeland, pasture, cropland and wildlife habitat. The principle crop is irrigated alfalfa. The potential native vegetation is mainly mid and short grasses with riparian shrubs near drainages.
DISTRIBUTION AND EXTENT: Clearcreek soils are of limited extent in the intermountain valleys of northwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sanders County, Montana; 1997
REMARKS: Soil interpretation record: MT1221. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 6 inches (A horizon); a particle size control section from 10 to 40 inches. Clearcreek soils have a frigid temperature regime and an aridic bordering on xeric moisture regime.