LOCATION COOCREEK WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Haplustepts
TYPICAL PEDON: Coocreek loam, in an area of Byrnie-Coocreek-Byrnie, this solum Complex, 0 to 15 percent slopes in rangeland. (colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; reddish brown (5YR 4/4) loam, dark reddish brown (5YR 3/4) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine and common medium roots; few very fine and fine continuous random irregular pores; 2 percent gravel; strong effervescent, calcium carbonate disseminated; 5 percent calcium carbonate equivalent; slightly alkaline (pH 7.6); clear smooth boundary. (4 to 12 inches thick)
Bw--5 to 12 inches; yellowish red (5YR 5/6) loam, reddish brown (5YR 4/4)moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many fine and very fine and common medium roots; common very fine and fine continuous random irregular pores; 8 percent gravel; strong effervescent, calcium carbonate disseminated; slightly alkaline (pH 7.8); gradual wavy boundary. (7 to 17 inches thick)
Bk--12 to 60 inches; yellowish red (5YR 5/6) loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine continuous random irregular pores; 7 percent gravel; violently effervescent, calium carbonate disseminated; 8 percent calcium carbonate equivalent; moderately alkaline (pH 8.0);
TYPE LOCATION: Platte County, Wyoming; 2,000 feet west and 100 feet north of the southeast corner of section 25, T. 20 S., R. 69 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 4 and 12 inches; dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Depth to Bk horizon - 10 to 21 inches.
Fine sand or coarser: 35 to 45 percent
Reaction: slightly alkaline or moderately alkaline
A horizon:
Hue: 5YR
Value: 3 or 4 moist
Chroma: 4
Texture: loam
Clay content: 18 to 25 percent
Rock fragments: 0 to 5 percent channers
Reaction: pH 6.6 to 8.4
Bw horizon - Hue: 5YR, or 7.5YR
Value: 3 or 4 moist
Chroma: 4, to 6
Texture: loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 7.4 to 8.4
Bk horizon:
Hue: 2.5YR, 5YR, or 7.5YR
Value: 4 or 5
Chroma: 3 or 4
Clay content: 18 to 27 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Cooers (MT) - is derived from baked hard sandstone (Scoria) and shale.
Delpoint (MT) - has a paralithic contact within a depth of 40 inches.
Spinekop (MT) - has hue yellower than 7.5YR; is stratified at depths of 18 to 45 inches.
Trudau (MT) - has hue yellower than 7.5YR; has a Bkz horizon at a depth of 30 inches.
Yamacall (T)(MT) - has hue of 10YR or yellower in the surface, cambic, and Bk horizons.
GEOGRAPHIC SETTING:
Landform - hills.
Elevation - 6,000 to 6,700 feet.
Slope- 0 to 5 percent.
Parent material - colluvium and alluvium derived from reddish colored sedimentary rocks.
Climate - cool with cold, dry winters; moist springs; warm summers.
Mean annual precipitation - 12 to 15 inches.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free season - 85 to 110 days.
DRAINAGE AND PERMEABILITY: Well drained; low runoff; moderate permeability.
USE AND VEGETATION: Coocreek soils are used for rangeland and wildlife habitat. The native vegetation is western wheatgrass, needleandthread, little bluestem, blue grama, winterfat, and big sagebrush.
DISTRIBUTION AND EXTENT: Southeastern Montana; LLR=E, MLRA 49; The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Platte County, Wyoming.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
the
Ochric epipedon - 0 to 5 inches (A horizon).
Cambic horizon - 5 to 12 inches (Bw horizon);
Coocreek soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.