LOCATION PIKADEN IDEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed Xeric Haplocryepts
TYPICAL PEDON: Pikaden extremely gravelly silt loam; supporting a Douglas-fir/common juniper habitat type, woodland; on a 55 percent slope with a northwest aspect at 7720 feet elevation. (Colors are for dry soil unless otherwise noted.)
0i--0 to 0.5 inches; forest litter of needles; 15 percent pebbles, 10 percent cobbles, trace stones; abrupt broken boundary. (0 to 4 inches thick)
A--0.5 to 5 inches; brown (10YR 4/3) extremely gravelly silt loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure parting to weak very fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine, few medium and coarse roots; many very fine irregular pores; 60 percent pebbles, 5 percent cobbles; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 9 inches thick)
Bw--5 to 12 inches; light brownish gray (10YR 6/2) extremely gravelly loam, dark grayish brown (10YR 4/2) moist; weak very fine granular structure; soft very friable, nonsticky and slightly plastic; many very fine, few medium and coarse roots; many very fine irregular pores; many faint coats of silt on upper surface of rock fragments; 80 percent pebbles, 5 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (6 to 16 inches thick)
BC--12 to 27 inches; light brownish gray (10YR 6/2) extremely gravelly loamy sand, grayish brown (10YR 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine, few medium and coarse roots; many very fine tubular pores; many faint coats of silt on upper surface of rock fragments; 80 percent pebbles, 5 percent cobbles; neutral (pH 6.6); gradual smooth boundary. (3 to 25 inches thick)
C--27 to 60 inches; fragmental; single grain; loose; common very fine roots; many coarse irregular pores; many coats of silt and sand on upper surfaces of rock fragments; 95 percent pebbles, 5 percent cobbles.
TYPE LOCATION: Clark County, Idaho; about 20 miles north and 28 miles west of Dubois Idaho; about 100 feet west and 1950 feet north of the southeast corner of section 15, T. 13 N., R. 31 E.; Latitude - 44 degrees North, 27 minutes, 11 seconds; Longitude - 112 degrees West, 47 minutes, 50 seconds.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 34 to 40 degrees F.
Mean summer soil temperature - 45 to 49 degrees F. with an O horizon, 46 to 52 degrees F. without an O horizon
Moisture control section - between 12 and 36 inches; dry throughout the moisture control section for 45 to 60 consecutive days during the four months following the summer solstice
O horizon thickness - absent to 4 inches
Ochric epipedon thickness - 2 to 7 inches
Depth to BC horizon - 10 to 20 inches
Depth to fragmental material - 25 to greater than 50 inches
A horizon
Hue - 7.5YR through 2.5Y
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 or 3 dry or moist
Reaction - slightly acid or neutral
Bw horizon
Hue - 7.5YR or 10YR
Value - 5 or 6 dry, 4 or 5 moist
Chroma - 2 or 3 dry or moist
Texture - sandy loam, loam or silt loam
Clay content - 2 to 10 percent
Rock fragments - 60 to 90 percent
Pebbles - 60 to 80 percent
Cobbles - 0 to 5 percent
Stones - 0 to 5 percent
Reaction - moderately acid to neutral
BC horizon
Hue - 5YR through 10YR
Value - 6 or 7 dry, 5 or 6 moist
Chroma - 2 or 3 dry or moist
Texture - loamy sand or sand
Clay content - 1 to 4 percent
Rock fragments - 70 to 90 percent
Pebbles - 35 to 80 percent
Cobbles - 5 to 45 percent
Stones - 0 to 5 percent
Reaction - moderately acid to neutral
C horizon
Rock fragment content - 90 to 100 percent
COMPETING SERIES: These are the Pirapeak, Struggle, and Underdown series. None of these soils have horizons containing fragmental material. In addition, Pirapeak soils have albic horizons and Underdown soils are moderately deep to a paralithic contact.
GEOGRAPHIC SETTING: Pikaden soils are on convex mountain sideslopes. Slopes range from 40 to 65 percent. The soils formed in slope alluvium and colluvium derived from quartzite and loess. Elevations are 7500 to 9800 feet. The climate is cold and moist in the winter and cool and dry in the summer. The mean annual precipitation is 18 to 24 inches. The mean annual temperature is 32 to 39 degrees F. The frost-free period is 10 to 40 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gany and Povey soils. Gany soils are on adjacent mountain sideslopes and are derived from limestone. They have a mollic epipedon, calcic horizon and loamy-skeletal particle size control section. Povey soils are on adjacent mountain sideslopes. They have a mollic epipedon greater than 16 inches thick and loamy-skeletal particle size control section.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderately rapid permeability; low runoff.
USE AND VEGETATION: Pikaden soils are used for recreation and wildlife habitat. These soils commonly support the Douglas-fir/common juniper plant association on north facing slopes and the Douglas-fir/Idaho fescue plant association on south facing slopes.
DISTRIBUTION AND EXTENT: Southeastern and eastcentral Idaho. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Targhee National Forest, Fremont County, Idaho, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the mineral soil surface to 5 inches (the A horizon).
Cambic horizon - the zone from 5 to 12 inches (the Bw horizon).
Particle size control section - the zone from 10 to 40 inches (part of the Bw, the BC and part of the C horizons).
Moisture regime - Xeric
The 3/2008 description reflects a change in classification from Sandy-skeletal, mixed Xeric Eutrocryepts Sandy-skeletal, mixed Xeric Haplocryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.