LOCATION COLSAVAGE WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, frigid Ustic Torriorthents
TYPICAL PEDON: Colsavage clay loam - on a southwest-facing slope of 8 percent; utilized as rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 5 inches; grayish brown (10YR 5/2) clay loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; slightly hard, firm, sticky and plastic; many very fine roots; slightly effervescent, lime is disseminated; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 6 inches thick)
Bw--5 to 10 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure; hard, firm, sticky and plastic; many very fine and common fine roots; slightly effervescent, lime is disseminated; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 6 inches thick)
Bk--10 to 30 inches; light brownish gray (2.5Y 6/2) clay, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; few fine roots; strongly effervescent, lime is disseminated; moderately alkaline (pH 8.4); clear wavy boundary.
Cr--30 inches; soft, calcareous shale.
TYPE LOCATION: Weston County, Wyoming; 1,200 feet south and 850 feet east of the NW corner, sec. 7, T. 48 N., R. 62 W.
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 20 to 40 inches. These soils are usually calcareous to the surface but are leached in some pedons. The control section contains more than 15 percent coarser than very fine sand. The mean annual soil temperature is 42 to 47 degrees F., and the mean annual summer soil temperature is 59 to 69 degrees F.
The A horizon ranges in hue from 5Y through 10YR, value from 5 through 7 dry, 3 through 5 moist, and chroma of 1 through 3. When the value of the A horizon is as dark as 5 dry and 3 moist, the horizon is too thin to qualify for a mollic epipedon. Texture is a clay loam or clay with 35 to 50 percent clay. Reaction is mildly to moderately alkaline.
The Bw horizon, when present, has the same range as the A horizon. It is a structured Bw horizon.
The Bk horizon has hue of 5Y through 2.5Y, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 or 3. Texture is clay or clay loam with clay ranging from 35 to 55 percent. Lime is disseminated or as few soft masses and contains about 2 to 8 percent calcium carbonate equivalent. It is moderately or strongly alkaline. Salinity is 2 to 4 mmhos.
COMPETING SERIES: These are the Dollard, Gunsone, Nobe, Rhoamett, Sunburst, and Vanda series. Dollard soils have less than 15 percent fine sand or coarser in the particle size control section and have a uniform precipitation with June as the driest month. Gunsone, Nobe, Rhoamett, Sunburst, and Vanda soils lack a paralithic contact above 40 inches. In addition, Gunsone soils have hue of 7.5YR or redder, Nobe soils have an EC of from 15 to 25 mmhos, and Vanda soils have an ESP of 20 to 30 percent.
GEOGRAPHIC SETTING: Colsavage soils are on dissected fan piedmonts and rolling hills controlled by bedrock of moderate depths. Slopes are typically 2 to 30 percent. The soils formed in residuum from calcareous shale. Elevation is 4,600 to 6,000 feet. The average annual precipitation is 15 to 19 inches. The average annual temperature is 42 to 47 degrees F. The frost-free season is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Samoist soils. The Samoist soils have a paralithic contact at 10 to 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: These soils are used for rangeland. Native vegetation consists of western wheatgrass, green needlegrass, blue grama, Columbia needlegrass, and big sagebrush.
DISTRIBUTION AND EXTENT: Black Hills Area of Northeast Wyoming.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Weston County, Wyoming; 1983.