LOCATION CLOUD PEAK WY+CO MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryalfs
TYPICAL PEDON: Cloud Peak silt loam-forested. (Colors are for dry soil unless otherwise stated.)
Oi--0 to 3 inches; undecomposed organic material, chiefly needles, twigs, bark, and grass remains.
Oe--3 to 4 inches; partially decomposed organic material like that of the horizon above.
A--4 to 5 inches; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; strong fine crumb structure; soft, very friable; noneffervescent; 10 percent limestone fragments; neutral (pH 6.6); clear smooth boundary. (0 to 3 inches thick)
E--5 to 8 inches; pinkish gray (7.5YR 6/2) very fine sandy loam, brown (7.5YR 5/2) moist; moderate thin platy structure that parts to moderate fine granules; soft, very friable; noneffervescent; 15 percent limestone fragments; neutral (pH 6.6); clear smooth boundary. (2 to 6 inches thick)
Bt1--8 to 22 inches; brown (7.5YR 5/4) very gravelly silty clay loam, dark brown (7.5YR 5/4) moist; moderate fine and medium subangular blocky structure; very hard, very friable, sticky and plastic; continuous faint clay films on faces of peds and lining pores; noneffervescent; 45 percent limestone pebbles and 15 percent cobbles; neutral (pH 7.2); gradual wavy boundary. (10 to 20 inches thick)
Bt2--22 to 26 inches; brown (10YR 5/3) very gravelly loam, dark brown (10YR 4/3) moist; weak medium subangular blocky structure; very hard, very friable, slightly sticky and slightly plastic; few faint clay films on faces of peds and in some root channels; noneffervescent; 45 percent limestone pebbles and 15 percent cobbles; slightly alkaline (pH 7.8); gradual wavy boundary. (0 to 8 inches thick)
Bk--26 to 36 inches; brown (10YR 5/3) extremely cobbly loam, dark brown (10YR 4/3) moist; massive; hard, very friable; violently effervescent, secondary calcium carbonate occurring as common nodules, in thin seams and streaks, and as coatings on rock fragments; 50 percent limestone cobbles and 20 percent pebbles; moderately alkaline (pH 8.0); gradual wavy boundary. (4 to 25 inches thick)
R--36 inches; limestone.
TYPE LOCATION: Johnson County, Wyoming; just south of Flagels mill site in the SW1/4 of sec. 23, T. 45 N., R. 85 W.
RANGE IN CHARACTERISTICS: Depth to calcareous material ranges from 12 to 24 inches. Depth to a lithic contact ranges from 20 to 40 inches. Content of organic carbon ranges from 1 to 5 percent in a thin A horizon but decreases rapidly and uniformly with increasing depth. The soil is 90 to 100 percent base saturated. The mean annual soil temperature ranges from 32 to 47 degrees F., and the mean summer soil temperature from 32 to 47 degrees F.
The E horizon has hue of 2.5Y through 7.5YR, value of 5 through 7 dry, 3 through 6 moist, and chroma of 2 through 4. This horizon is soft or slightly hard and slightly acid or neutral.
The Bt horizon has hue of 2.5Y through 5YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 6. The matrix material is typically silt loam or silty clay loam, but clay ranges from 18 to 35 percent, silt from 35 to 60 percent, and sand from 10 to 45 percent. Rock fragments range from 35 to 60 percent pebbles and 0 to 20 percent cobbles or stones or both.
The Bk horizon has hue of 2.5Y through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 6. It has 2 to 12 percent calcium carbonate equivalent in the fine earth portion. Texture of the matrix is loam, clay loam, or silty clay loam modified with 10 to 35 percent pebbles and 45 to 55 percent cobbles or stones or rocks. Reaction is slightly through strongly alkaline.
COMPETING SERIES: These are the Cadotte, Cundiyo, Guffey, Kimpton, Lake Creek, Lakehelen, Losee, Lulude, and Macfarlane series. Cadotte, Cundiyo, Losee and Macfarlane soils are very deep. Kimpton soils have more than 12 percent calcium carbonate equivalent. Lulude soils have a E/B horizon and no secondary carbonate accumulation. Guffey and Lake Creek soils do not have horizons of carbonate accumulation. Lakehelen soils have reaction of slightly acid or moderately acid throughout. Tepecreek soils are moderately deep to a paralithic contact and deep to a lithic contact.
GEOGRAPHIC SETTING: These soils are on shoulders, footslopes, summits and crests of hills and mountains. Elevation is 5,400 to 9,000 feet. Slopes range from 6 to 75 percent. The soils formed in material weathered from limestone. At the type location the average annual precipitation is 20 inches with peak periods of precipitation during the spring and early summer. The average annual temperature is 36 degrees F., and the average summer temperature is 53 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chubbs and Nathrop soils. Chubbs soils have less than 35 percent rock fragments. Nathrop soils have a mollic epipedon and lack an E horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Used as native pastureland, for recreation, and as timberland. Principal native plants are spruce, fir, and lodgepole pine with an understory of mountain brome and other grasses.
DISTRIBUTION AND EXTENT: West and north-central Wyoming and northern Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Johnson County (Southern Johnson County Area), Wyoming; 1971.
Diagnostic features and horizons recognized in this profile are: an ochric epipedon from 4 to 8 inches (A, E horizons); an argillic horizon from 8 to 26 inches (Bt1, Bt2 horizons); horizon of secondary calcium carbonate accumulation from 26 to 36 inches (Bk horizon); a lithic contact at 36 inches (R horizon).