LOCATION TONGUE RIVER WY+MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Eutric Haplocryalfs
TYPICAL PEDON: Tongue River silt loam-forested. (Colors are for dry soil unless otherwise stated.)
Oi--0 to 4 inches; organic material, mainly twigs, bark, and needles.
Oe--4 to 6 inches; organic material, partially decomposed organic material, needles, bark, and small twigs.
E--6 to 11 inches; light brownish gray (10YR 6/2) silt loam, grayish brown (10YR 5/2) moist; moderate thin platy structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; common fine, very fine, and few coarse roots; 5 percent channers; slightly acid (pH 6.4); clear irregular boundary. (1 to 8 inches thick)
Bt1--11 to 15 inches; grayish brown (10YR 5/2) silty clay loam, dark grayish brown (10YR 4/2) moist; moderate fine subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common fine, very fine, and few coarse roots; many faint clay films on faces of peds; 10 percent channers and 5 percent soft shale chips; slightly acid (pH 6.2); clear wavy boundary. (0 to 12 inches thick)
Bt2--15 to 26 inches; grayish brown (10YR 5/2) channery silty clay loam, dark grayish brown (10YR 4/2) moist; moderate fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common fine, very fine, and few coarse roots; continuous faint clay films on faces of peds; 15 percent channers and 5 percent soft shale chips; slightly acid (pH 6.1); gradual smooth boundary. (7 to 16 inches thick)
BC--26 to 34 inches; light brownish gray (2.5Y 6.2) and light yellowish brown (2.5Y 6/4) channery silty clay loam, grayish brown (2.5Y 5/2) and light olive brown (2.5Y 4/4)
moist; weak medium subangular blocky structure; few fine and coarse roots; few faint clay films on faces of some peds; 20 percent channers and 5 percent soft shale chips; slightly acid (pH 6.4); gradual smooth boundary. (3 to 8 inches thick)
Cr--34 to 60 inches; soft sandstone interbedded with shale and siltstone.
TYPE LOCATION: Sheridan County, Wyoming; approximately 1/2 mile west of the SE corner of sec. 19, T. 55 N., R. 88 W.
RANGE IN CHARACTERISTICS: Depth to bedrock and paralithic contact ranges from 20 to 40 inches. The mean annual soil temperature ranges from 32 to 40 degrees F. and the mean summer soil temperature ranges from 42 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 6. Low moist values are due to the lithochromic mineral color, not organic carbon. Reaction is moderately acid through neutral.
When present the A horizon has hue of 2.5Y through 7.5YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 through 4.
The Bt horizon has hue of 5Y through 10YR, value of 4 through 7 dry, 3 through 5 moist, and chroma of 2 through 6. Matrix texture is silty clay loam, clay loam, loam or sandy clay loam with 20 to 35 percent clay and less than 35 but more than 15 percent fine or coarser sand. Sandstone and shale channers range from 0 to 25 percent. Soft shale chips range from 0 to 50 percent. Reaction is moderately acid through neutral.
The BC and C horizons, when present, have hue of 5Y through 10YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 3 through 8. Matrix texture is clay loam, loam, silty clay loam, sandy clay loam, and sandy loam with 10 to 50 percent channers and shale chips. Reaction in the BC horizon is moderately acid through neutral but may range to slightly alkaline in the C horizon.
The Cr horizon consists of interbedded sandstone, shale, and siltstone. The soil-bedrock contact is considered to be a paralithic contact. Thin, discontinuous strata of hard sandstone and slaty shale occur and serve as the parent source for the coarse fragments in the soil.
COMPETING SERIES: These are the Ericson, Haviland, Hierro, Indart, Jaegie, Sapphire, Swifton, Trapper, Weminuche, and Whitefish series. The Ericson, Haviland, Hierro, Jaegie, Swifton, Trapper, and Weminuche soils are very deep. Sapphire soils have a lithic contact at 20 to 40 inches. Indart soils formed in material from red beds and have hue of 5YR or redder in the Bt horizon. Whitefish soils contain continuous horizons of carbonate accumulation.
GEOGRAPHIC SETTING: Tongue River soils are on nearly level to steep mountain and hillslope positions. These soils formed in residuum and colluvial slopewash weathered from interbedded sandstone, shale, and siltstone. Slopes are 2 to 60 percent. Elevations are 5,500 to 9,500 feet. The mean annual precipitation is about 24 inches at the type location but ranges from 19 to 35 inches. The mean annual temperature is about 34 degrees F. but ranges from 32 to 38 degrees F. The frost-free season is estimated to range from 30 to 70 days, but frost may occur at any time.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buffork, Clayburn, Inchau, Mayoworth, and the competing Uinta series. The Buffork, Clayburn, Inchau, and Mayoworth soils have a mollic epipedon. Because of the micro relief these soils can occur in complex patterns with the Tongue River or as associated soils on contiguous land forms.
DRAINAGE AND PERMEABILITY: Well drained; medium or slow runoff; moderate permeability.
USE AND VEGETATION: Woodland, wildlife habitat, and recreation. Native vegetation is Engelmann spruce, Douglas fir, lodgepole pine with an understory of pinegrass, columbine, vaccinium, snowberry, and russet buffaloberry.
DISTRIBUTION AND EXTENT: Mountain areas of Wyoming and south central Montana. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sheridan County, Wyoming; 1932.
Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from 6 to 11 inches (E horizon); argillic horizons which are the particle-size control section from 11 to 26 inches (Bt horizons). Tongue River soils have a cryic temperature regime and a udic moisture regime.