LOCATION HIGHVALLEY IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, isotic, frigid Vitrandic Haploxerolls
TYPICAL PEDON: Highvalley ashy loam, forested -- on a southwest-facing slope of 35 percent at 5,660 feet elevation. When described on October 19, 1994, the soil was dry throughout. (Colors are for air-dry soil unless otherwise noted.)
Oi--0 to 1 inch; slightly decomposed forest litter.
A--1 to 5 inches; very dark grayish brown (10YR 3/2) ashy loam, very dark brown (10YR 2/2) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine, fine and medium irregular pores; 5 percent fine gravel; slightly acid (pH 6.1); clear smooth boundary. (2 to 10 inches thick)
AB--5 to 10 inches; brown (10YR 4/3) ashy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine, fine and medium irregular pores; 1 percent fine gravel; slightly acid (pH 6.1); clear wavy boundary. (0 to 10 inches thick)
Bw1--10 to 24 inches; brown (10YR 4/3) ashy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine, fine and medium tubular pores; 5 percent fine gravel; slightly acid (pH 6.5); gradual wavy boundary. (10 to 20 inches thick)
Bw2--24 to 48 inches; dark yellowish brown (10YR 4/4) ashy loam, dark yellowish brown (10YR 3/4) moist; weak medium prismatic structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine, fine and medium roots; many very fine, fine and medium tubular pores; 2 percent fine gravel; slightly acid (pH 6.5); gradual wavy boundary. (10 to 30 inches thick)
Bw3--48 to 66 inches; dark yellowish brown (10YR 4/6) ashy loam, dark yellowish brown (10YR 3/4) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine, fine and medium tubular pores; 2 percent fine gravel; slightly acid (pH 6.5).
TYPE LOCATION: Boise County, Idaho; about 4 miles north and 4 miles west of Banks; 1,500 feet south and 100 feet east of the northwest corner of section 11, T.9 N., R.2 E.; USGS High Valley Quadrangle; Latitude - 44 degrees, 08 minutes, 04 seconds N. and Longitude - 116 degrees, 11 minutes, 44 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 20 to 40 inches
Depth to base of vitrandic feature - 40 to 60 inches or more
Depth to bedrock - greater than 60 inches
Reaction - moderately acid or slightly acid
Base saturation - 50 to 75 percent
Particle-size control section - 17 to 27 percent clay; 0 to 15 percent rock fragments
Moisture control section - dry 45 to 75 consecutive days following summer solstice
Average annual soil temperature - 42 to 47 degrees F.
A horizon
Value - 3 or 4 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 14 to 20 percent
Rock fragments - 0 to 15 percent gravel
Volcanic glass content - 10 to 20 percent
Acid oxalate extract Al+1/2 Fe - 0.8 to 1.2 percent
AB horizon
Hue - 10YR or 7.5YR
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 or 3 dry or moist
Clay content - 16 to 25 percent
Rock fragments - 0 to 15 gravel
Volcanic glass content - 5 to 15 percent
Acid oxalate A1+1/2 Fe - 0.4 to 1.2 percent
Bw1 and Bw2 horizons
Hue - 10YR or 7.5YR
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 through 4 dry or moist
Clay content - 18 to 27 percent
Rock fragments - 0 to 15 percent
Volcanic glass content - 5 to 10 percent
Acid oxalate extract A1+1/2 Fe - 0.4 to 1.0 percent
Bw3 horizon
Hue - 10YR or 7.5YR
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 3 through 6 dry or moist
Clay content - 15 to 25 percent
Rock fragments - 0 to 15 gravel, 0 to 35 percent cobbles and 0 to 35 percent total
Volcanic glass content - 0 to 10 percent
Acid oxalate extract Al+1/2 Fe - 0 to 1.0 percent
COMPETING SERIES: These are the Buford, Derr (T), Hall Ranch, Kahler, McGarr, Minam and Myzel (T) series. Buford soils are 40 to 60 inches to bedrock and have buried Bw horizons. Derr soils are 20 to 40 inches deep to shale bedrock. Hall Ranch soils are 20 to 40 inches deep to paralithic contact. Kahler soils have vitrandic features to depths of 20 to 40 inches, typically over a lithologic discontinuity (2C horizons), has clay ranging to 35 percent and rock fragments ranging to 35 percent in the particle-size control section. Minam soils have 20 to 30 percent glass in the A horizon and 2C horizons with greater than 35 percent rock fragments within 20 to 30 inches. McGarr soils are 20 ro 40 inches to a lithic contact (basalt). Myzel soils are moderately well drained with seasonal high water table at 30 to 48 inches and average 27 to 35 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: Highvalley soils are on mountain slopes at elevations of 3,750 to 6,800 feet. These soils formed in colluvium from basalt and welded tuff mixed with volcanic ash throughout. Slopes range from 15 to 65 percent. The average annual precipitation is 26 to 36 inches. The average annual temperature is 40 to 45 degrees F. The frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hoff, Longs and Shilling soils. Hoff soils are shallow to bedrock on convex areas. Longs and Shilling soils are loamy-skeletal on similar geomorphic positions.
DRAINAGE AND PERMEABILITY: Well drained; rapid to very rapid runoff; moderate permeability.
USE AND VEGETATION: Highvalley soils are used mainly for timber production and woodland grazing. Native vegetation is Douglas-fir, ponderosa pine, grand fir, mountain maple and mallow ninebark.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 43b.
Highvalley soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Boise County Area, Idaho, Parts of Ada and Boise Counties, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - zone from the mineral soil surface to 24 inches (A, AB and Bw1 horizons)
Vitrandic feature - whole pedon (all mineral horizons)
Cambic horizon - zone from 24 to 66 inches (Bw2 and Bw3 horizons)
Particle-size control section - zone from 11 to 41 inches
Soil moisture regime - xeric
All depths related to diagnostic horizons and features listed in the range of characteristics are from the top of the first mineral horizon.
ADDITIONAL DATA: Reference sample no. S94ID-015-006 (NSSL pedon 95Z166).