LOCATION LEECREEK IDEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed Fluvaquentic Cryaquepts
TYPICAL PEDON: Leecreek silt loam -- on a nearly level flood plain at 5,200 feet elevation in pasture. (Colors are for dry soil unless otherwise noted.)
Oe--0 to 2 inches; moderately decomposed grass and roots.
Akg--2 to 5 inches; grayish brown (2.5Y 5/2) very dark grayish brown (2.5Y 3/2) moist silt loam; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, and common medium roots; common very fine and fine tubular pores; 5 percent gravel, violently effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (2 to 5 inches thick)
Bkg1--5 to 8 inches; light brownish gray (2.5Y 6/2) dark grayish brown (2.5Y 4/2) moist silt loam, few fine distinct masses of iron accumulation, light olive brown (2.5Y 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine and fine, and common medium roots; common very fine and fine tubular pores; 5 percent gravel; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary.
Bkg2--8 to 15 inches; light brownish gray (2.5Y 6/2) dark grayish brown (2.5Y 4/2) moist gravelly silt loam, common fine prominent masses of iron accumulation, light olive brown (2.5Y 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine and fine tubular pores; 25 percent gravel; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary.
Bkg3--15 to 20 inches; light brownish gray (2.5Y 6/2) dark grayish brown (2.5Y 4/2) moist very gravelly silt loam, few fine prominent masses of iron accumulation, light olive brown (2.5Y 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and fine tubular pores; 40 percent gravel; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (Combined thickness of the Bkg horizons is 11 to 20 inches)
2Bk--20 to 62 inches; multicolored extremely gravelly loamy coarse sand; single grain; loose, nonsticky and nonplastic; few very fine roots; common fine irregular pores; 75 percent gravel, 10 percent cobbles; violently effervescent; lime coatings on undersides of coarse fragments; moderately alkaline (pH 8.0).
TYPE LOCATION: Custer County, Idaho; about 3.5 miles northeast of Challis, Idaho; about 600 feet north and 2,350 feet east from the southwest corner of sec. 14, t.14N., R.19E.; Latitude - 44 degrees, 32 minutes, 20 seconds North; Longitude - 114 degrees, 10 minutes, 59 seconds West.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 36 to 40 degrees F.
Mean summer soil temperature - 39 to 43 degrees F.
Depth to high water table - 12 to 18 inches (April through October)
Depth to sand and gravel - 13 to 22 inches
Particle-size control section
Weighted average clay content - 5 to 10 percent
Weighted average sand content - 75 to 90 percent
Weighted average rock content - 35 to 75 percent
Rock fragments - 5 to 40 percent in the upper part and 60 to 90 percent in the lower part
Ak horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 or 2 dry or moist
Bkg horizons
Value - 5 through 7 dry, 4 or 5 moist
Chroma - 2 or 3 dry or moist
Texture - SIL, GR-SIL, GRV-SIL
Rock fragments - 5 to 40 percent
Clay content - 5 to 25 percent
2Bk horizon
Texture - GRX-LS or GRX-LCOS
Rock fragments - 60 to 90 percent
Clay content - 0 to 5 percent
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Leecreek series are on flood plains and stream terraces. Slopes are 0 to 3 percent. Elevation ranges from 4,900 to 7,400 feet. The soil formed in mixed alluvium over flood deposited sand and gravel. The climate is cold and moist in winter and spring and cool in summer. The average annual precipitation is 8 to 12 inches. Average annual air temperature is 36 to 42 degrees F. Frost-free period is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lemroi and Grandjean series. Lemroi soils are on smooth positions on valley flats and have loamy-skeletal particle-size control sections. Grandjean soils are in concave positions and are very poorly drained.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; moderate permeability in the upper part of the profile and very rapid permeability in the lower part. This soil floods occasionally for brief periods in January through June.
USE AND VEGETATION: Mostly for grass hay and pasture. The principle native vegetation is slender wheatgrass and sedges.
DISTRIBUTION AND EXTENT: East-central Idaho. This series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Custer County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Particle-size control section - the zone from 12 to 42 inches (part of the Bkg2, the Bkg3, and part of the 2Bk horizons)
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.