LOCATION LEMROI IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Cryaquolls
TYPICAL PEDON: Lemroi loam -- on a nearly level flood plain at 5,200 feet elevation in pasture. (Colors are for dry soils unless otherwise noted. When described on August 3, 1987, the soils was moist from the surface to 18 inches and saturated below 18 inches. A water table was present at 18 inches.)
Oe--0 to 3 inches; moderately decomposed grasses.
A1--3 to 11 inches; dark gray (10YR 4/1) silt loam, black (10YR 2/1) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, and common medium roots; common very fine and fine tubular pores; 2 percent gravel; moderately alkaline (pH 8.0); clear smooth boundary.
A2--11 to 14 inches; dark gray (10YR 4/1) silt loam, black (10YR 2/1) moist; few fine distinct masses of iron depletion dark grayish brown (10YR 4/2) dry; moderate medium subangular blocky structure; slightly hard, 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; slightly alkaline (pH 7.8); clear smooth boundary.
A3--14 to 18 inches; dark gray (10YR 4/1) gravelly silt loam, black (10YR 2/1) moist; common fine prominent masses of iron depletion light olive brown (2.5Y 5/4) dry; moderate medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; 15 percent gravel; slightly alkaline (pH 7.8); clear wavy boundary. (Combined thickness of A horizons 10 to 20 inches.)
Bg--18 to 26 inches; light gray (10YR 7/1) extremely gravelly loam, dark grayish brown (2.5Y 4/2) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and fine tubular pores; 70 percent fine gravel, 5 percent cobbles; slightly alkaline (pH 7.8); clear wavy boundary. (8 to 20 inches thick)
2Cg--26 to 63 inches; gray (10YR 6/1) extremely gravelly loamy coarse sand, dark grayish brown (2.5Y 4/2) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; common fine irregular pores; 75 percent gravel, 10 percent cobbles; slightly alkaline (pH 7.8).
TYPE LOCATION: Lemhi County, Idaho; approximately 2 miles southwest of May, Idaho; about 1,000 feet east and 1,100 feet south from the northwest corner of sec. 36, T.15N., R.21E. Latitude - 44 degrees, 35 minutes, 30 seconds North. Longitude - 113 degrees, 55 minutes, 40 seconds West.
RANGE IN CHARACTERISTICS:
Mean summer soil temperature - 39 to 43 degrees F.
Mean annual soil temperature - 34 to 40 degrees F.
Depth to high water table - 6 to 12 inches (April through October)
Depth to sand and gravel - 20 to 30 inches
Particle-size control section:
Weighted average clay content - 5 to 18 percent
Weighted average sand content - 50 to 75 percent
Weighted average rock content - 35 to 75 percent
Rock fragment content - 5 to 15 percent in the upper part (A horizons) and 60 to 90 percent in the lower part (Bg and 2Cg horizons)
A horizon:
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 or 2 dry or moist
Clay content - 5 to 25 percent
Bg horizon:
Texture - GRX-L and GRX-SL
Rock fragments - 60 to 90 percent
Clay content - 5 to 18 percent
2Cg horizon:
Texture - GRX-LS or GRX-LCOS
Rock fragments - 60 to 90 percent
Clay content - 0 to 5 percent
COMPETING SERIES: These are the Finn and Mahaffey series. Finn soils average over 18 percent clay in the particle-size control section. Mahaffey soils have sand and gravel at 30 to 40 inches and a high water table at 24 to 42 inches.
GEOGRAPHIC SETTING: Lemroi series are on flood plains, stream terraces and valley flats. These soils formed in mixed alluvium over flood deposited sand and gravel. Slopes are 0 to 3 percent. Elevation ranges from 5,800 to 7,400 feet. 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 40 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fezip and Redfish series. Fezip soils are on smooth positions on valley flats and have coarse-loamy particle-size control sections. Redfish soils are in concave positions and are sandy-skeletal.
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: Lemhi County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 3 to 18 inches (A horizons)
Cambic horizon - the zone from 18 to 26 inches
Particle-size control section - the zone from 13 to 43 inches (part of the A2, the A3, Bg, and part of the Cg horizons)
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.