LOCATION ROCKYBAR IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Mollic Haploxeralfs
TYPICAL PEDON: Rockybar extremely cobbly loam - on a 7 percent slope in rangeland. When described on September 26, 1980, the soil was moist to a depth of 15 inches. (Colors are for dry soil unless otherwise noted).
A--0 to 5 inches; yellowish brown (10YR 5/4) extremely cobbly loam, dark brown (10YR 3/3 moist; weak fine granular structure; soft, very friable, slightly sticky; many very fine, fine, and medium roots; many very fine and fine interstitial pores; about 20 percent stones, 30 percent cobbles, and 15 percent pebbles; neutral (pH 6.8); clear smooth boundary.
BA--5 to 9 inches; yellowish brown (10YR 5/4) extremely cobbly
loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine and fine interstitial pores; about 15 percent stones, 30 percent cobbles, 15 percent pebbles; neutral (pH 7.0); clear smooth boundary.
Bt1--9 to 20 inches; light yellowish brown (10YR 6/4) extremely cobbly loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; about 10 percent stones, 40 percent cobbles and 15 percent pebbles; few thin clay films on ped faces and lining pores; neutral (pH 7.0); gradual wavy boundary.
Bt2--20 to 31 inches; light yellowish brown (10YR 6/4) extremely cobbly clay loam, dark yellowish brown (10YR 4/4) moist; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; about 10 percent stones, 40 percent cobbles, and 15 percent pebbles; few thin clay films on ped faces and lining pores and on rock fragments; neutral (pH 7.2); gradual wavy boundary.
BC--31 to 47 inches; light yellowish brown (10YR 6/4) extremely cobbly loam, yellowish brown (10YR 5/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and fine interstitial pores; about 10 percent stones, 40 percent cobbles and 15 percent pebbles; neutral (pH 7.2); clear wavy boundary.
C--47 to 62 inches; yellowish brown (10YR 5/4) extremely cobbly
loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine interstitial pores; about 10 percent stones, 35 percent cobbles; and 25 percent pebbles; slightly acid (pH 6.6).
TYPE LOCATION: Blaine County, Idaho, about 13 miles north of Carey; 900 feet south and 2,000 feet west of the northeast corner, sec. 15, T. 2 N, R 21 E.
RANGE IN CHARACTERISTICS:
Annual soil temperature - 42 to 47 degrees F
Thickness of solum - 30 to 48 inches
Reaction - slightly acid to neutral
Depth to bedrock - greater than 60 inches
A horizon
Color value, dry - 4 or 5
Chroma, moist or dry - 3 or 4
BA horizon
Color value, dry - 4 or 5
Color value, moist - 3 or 4
Rock fragments - 60 to 80 percent
Clay content - 15 to 25 percent
Bt horizons
Color hue - 7.5YR or 10YR
Color value, dry - 5 or 6
Color value, moist - 4 or 5
Rock fragments - 60 to 80 percent
Texture - CBX-L, CBX-CL
Clay content - 25 to 33 percent
BC and C horizons
Color hue - 7.5YR or 10YR
Color value, dry - 5 or 6
Color value, moist - 4 or 5
Chroma, dry or moist - 4 to 6
Rock fragments - 60 to 80 percent
Clay content - 15 to 27 percent
Texture - CBX-SL, CBX-L
COMPETING SERIES: These are the Etchen and Hat (T) series. Etchen and Hat soils have lithic contact at a depth of 20 to 40 inches.
GEOGRAPHIC SETTING: Rockybar soils are on outwash terraces. Slopes range from 2 to 30 percent. Elevation ranges 5,500 to 6,500 feet. The soil formed in glacial outwash from mixed igneous and metamorphic rock. The annual precipitation ranges from 12 to 16 inches, most of which falls as snow and early spring rain. The annual air temperature is about 40 to 45 degrees F. The frost-free season is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Friedman, Little Wood, and Starhope soils. Friedman soils have mollic epipedons greater than 10 inches thick. Little Wood soils have mollic epipedons. Starhope soils have mollic epipedons and are moderately deep. Little Wood soils occur on stream terraces. Friedman and Starhope soils occur on foothills and mountainsides.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is moderate to high. Permeability is moderate.
USE AND VEGETATION: Mainly used for rangeland. Vegetation is mountain big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: South-central Idaho. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Diagnostic horizons and features recognized in this soil are:
Ochric epipedon - surface to 9 inches (A and BA horizons)
Argillic horizon: the zone from approximately 9 to 31 inches.