LOCATION HOOVERTON IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Typic Argixerolls
TYPICAL PEDON: Hooverton stony loam -- on a 52 percent west-facing slope at 3,980 feet elevation in native grassland. When described on October 7, 1991, the soil was dry throughout. (Colors are for dry soil unless otherwise stated).
A--0 to 11 inches; very dark grayish brown (10YR 3/2) stony loam, very dark brown (10YR 2/2) moist; strong fine and medium granular structure; soft, friable, nonsticky and slightly plastic; many fine and very fine and few medium roots throughout; common fine and very fine tubular pores; 20 percent gravel, 3 percent cobbles, 3 percent stones; neutral (pH 6.8); clear wavy boundary (4 to 12 inches thick).
BA--11 to 17 inches; brown (10YR 4/3) very cobbly loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots throughout; common fine and very fine tubular pores; 15 percent gravel, 25 percent cobbles; neutral (pH 6.8); clear wavy boundary (0 to 8 inches thick).
Bt1--17 to 26 inches; dark yellowish brown (10YR 4/4) very cobbly clay loam, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; few fine roots matted around rock fragments; many very fine tubular pores; very few faint patchy clay films on faces of peds; 15 percent gravel, 40 percent cobbles, 5 percent stones; neutral (pH 6.8); clear wavy boundary.
Bt2--26 to 35 inches; dark yellowish brown (10YR 4/4) extremely cobbly clay loam, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; few fine roots matted around rock fragments; common very fine tubular pores; very few faint patchy clay films on faces of peds; 10 percent gravel, 60 percent cobbles, 5 percent stones; slightly acid (pH 6.4); clear wavy boundary (combined thickness of the Bt horizons is 10 to 28 inches).
R--35 inches; fractured basalt.
TYPE LOCATION: Lewis County, Idaho; about 11 miles south of Winchester, about 750 feet north and 1000 feet east of the southwest corner of section 30, T. 32 N., R.2 W. Latitude - 46 degrees, 04 minutes, 49 seconds N, Longitude - 116 degrees, 38 minutes, 42 seconds W.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 10 to 18 inches
Base saturation - 75 to 100 percent
Depth to bedrock - 24 to 40 inches
Average annual soil temperature - 47 to 52 degrees F
Consecutive days dry in moisture control section - 60 to 90
Particle size control section (weighted averages)
Clay content - 24 to 34 percent
Rock fragment content - 60 to 80 percent
A horizon
Hue - 7.5YR or 10YR
Value - 3 through 5 dry, 2 or 3 moist
Chroma - 2 through 4 dry
Reaction - slightly acid or neutral
BA horizon
Hue - 7.5YR or 10YR
Value - 3 or 4 dry
Chroma - 2 or 3, dry or moist
Textures - CBV-L, CBV-SIL, GRV-SIL
Rock fragments - 35 to 50 percent
Clay content - 20 to 27 percent
Reaction - slightly acid or neutral
Bt horizons
Hue - 7.5YR or 10YR
Value - 3 or 4, dry or moist
Textures - CBV-CL, CBX-CL, GRV-SICL, GRX-SIL, GRV-L, CBV-SIL
Rock fragments - 50 to 85 percent
Clay content - 24 to 34 percent
Reaction - slightly acid to neutral
COMPETING SERIES: These are the Baboon, Badge, Collard, Dixiejet, Goodnoe, Kusshi, Phys, Ridd, and Whitinger soils. Baboon and Whitinger soils have 35 to 60 percent rock fragments in the particle-size control section. Badge soils are deep or very deep to bedrock. Collard, Kusshi, and Phys soils are very deep. Dixiejet soils are deep to a lithic contact. Goodnoe soils are dry for 90 to 105 days following the summer solstice.
GEOGRAPHIC SETTING: Hooverton soils are on south- and west-facing canyon sides. Slopes range from 35 to 75 percent. These soils formed in colluvium from basalt with some minor additions of loess and volcanic ash in the upper part. Elevations are 2,800 to 5,300 feet. Average annual precipitation is 22 to 28 inches, average annual temperature is 44 to 50 degrees F., and the frost free period is 70 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Klickson and Kettenbach series. Klickson soils are greater than 60 inches deep, have less than 75 percent base saturation in some part, and are on north- and east-facing canyon sides. Kettenbach soils have a thick mollic epipedon and are on south- and west-facing canyon sides at lower elevations.
DRAINAGE AND PERMEABILITY: Well drained; moderate to very rapid runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for wildlife habitat and livestock grazing. Native vegetation is mainly bluebunch wheatgrass, Idaho fescue, arrowleaf balsamroot, and silky lupine.
DISTRIBUTION AND EXTENT: This soil is moderately extensive in the canyons of north-central Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lewis County, Idaho, 1995.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 17 inches (the A and BA horizons).
Argillic horizon (and particle-size control section) - The zone from 17 to 35 inches (the Bt1 and Bt2 horizons).