LOCATION DRA ID+WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Xeric Argicryolls
TYPICAL PEDON: Dra silt loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; very weak medium platy parting to moderate very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine tubular pores; few angular pebbles, cobblestones, and stones; common uncoated silt grains; slightly acid (pH 6.4); abrupt smooth boundary. (0 to 3 inches thick)
A2--2 to 9 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; very weak very coarse prismatic parting to weak medium subangular blocky, then to moderate medium and fine granular structure; hard, friable, slightly sticky and slightly plastic; common fine and few medium and coarse roots; many very fine tubular and interstitial pores; about 15 percent white angular gravel and few cobblestones and stones; common uncoated silt grains; neutral (pH 6.8); clear wavy boundary. (5 to 12 inches thick)
Bt1--9 to 12 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; slightly darker coatings on blocks, dark grayish brown (10YR 4/2) dry; moderate fine subangular blocky parting to weak medium and fine granular structure; hard, friable, slightly sticky and slightly plastic; few fine, medium, and coarse roots; many very fine tubular pores; about 10 percent angular gravel and few cobblestones and stones; few to common uncoated silt grains; faint patchy clay films in the channels; very few, half-inch krotovinas having the same color and texture as the A2 horizon; neutral (pH 7.0); clear smooth boundary. (2 to 5 inches thick)
Bt2--12 to 21 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; weak medium prismatic parting to moderate medium and fine subangular blocky structure; hard, friable, sticky and plastic; few very fine, fine, and medium roots; many very fine tubular pores; few angular gravel, cobblestones, and stones; thin patchy or nearly continuous clay films on peds and in channels, which are brown (10YR 5/3) dry and dark brown (10YR 3/3) moist; common uncoated silt grains on peds; few half-inch, 10YR 3/2 (dry) krotovinas or filled cicada holes; noncalcareous except larger rock fragments are coated with calcium carbonate on the lower side; neutral (pH 7.0); abrupt wavy boundary. (6 to 12 inches thick)
Bk--21 to 32 inches; pale brown (10YR 6/3) very stony loam, brown (10YR 5/3) moist; weak medium and fine subangular blocky structure; hard , friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine tubular pores; strongly effervescent; moderately alkaline (pH 7.9); abrupt irregular boundary. (1 to 15 inches thick)
R--32 inches; fractured fine-grained sandstone with small quantity of soil material in the cracks.
TYPE LOCATION: Teton County, Idaho; 210 feet northeast along road from fence and 65 north from road about 1.1 miles southeast of Victor; 600 feet east and 850 feet south of the northwest corner of the SE1/4 section 12, T.3N., R.45E.
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 20 to 40 inches, and the thickness of the solum and the depth to calcareous material ranges from 20 to 32 inches. The soil between depths of 4 and 12 inches is dry for 45 to 60 consecutive days during mid and late summer. The mean annual soil temperature is about 38 to 45 degrees F. and the mean summer soil temperature is 57 to 60 degrees F. The mollic epipedon is 10 to 16 inches thick.
The A horizon has value of 3 or 4 dry, 1 or 2 moist, and chroma of 2 or 3. It is silt loam or loam, and in some pedons is gravelly, cobbly, stony, or very stony. This horizon is slightly acid or neutral.
The Bt horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry, 4 moist and chroma of 3 or 4 moist and dry. It is clay loam or silty clay loam and has less than 35 percent clay. Rock fragments range from 0 to 15 percent.
The Bk horizon ranges from about 5 to 18 percent in carbonates, and contains 10 to 50 percent rock fragments.
COMPETING SERIES: These are the Amsden, Croydon, Celkie, Hourglass, Kezar, Leavitt, Lucky, Lymanson, Lyonman, Michelson, Miracle, Monad, Morset, Mult, Newlands, Passcreek, Philipsburg, Rammel, Sponseller, Tingey, Tripit, Wellsville, Woosley, and Youga series. Amsden, Croydon, Gelkie, Hourglass, Leavitt, Lyonman, Michelson, Monad, Morset, Philipsburg, Tingey, Wellsville, and Youga soils are deeper than 40 inches to bedrock. Kezar soils have a large proportion of coarse and very coarse angular sand and are extremely hard when air dry. Lucky, Mult, and Newlands soils are noncalcareous in the lower part of the solum, and lack continuous subhorizons of secondary calcium carbonate accumulation. Lymanson and Tripit soils have a paralithic contact at depths of less than 40 inches. Miracle and Sponseller soils have hue of 5YR or redder in a major part of the control section. Passcreek soils have a solum less than 20 inches thick. Rammel soils have less than 27 percent clay and have 15 to 50 percent rock fragments in the Bt horizon. Woosley soils have 5 to 15 percent fine limestone gravel in all parts of the soil profile, and have developed in residuum from limestone.
GEOGRAPHIC SETTING: Dra soils are on uplands and have gradients of 2 to 60 percent, dominantly 12 to 40 percent. The soils formed in residuum weathered from fine-grained sandstone. In places, a small percentage of limestone of an admixture of loess is present. Elevations are 6,000 to 7,000 feet. The cool, subhumid, continental climate has warm, dry summers and cool, moist winters. Mean annual precipitation is 16 to 20 inches. The mean annual temperature is 36 degrees to 43 degrees F. Frost-free season is about 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Rammel soils and the Dranyon, Mikesell, and Ridgecrest soils. Dranyon soils are noncalcareous and have a mollic epipedon thicker than 16 inches. Mikesell soils have an albic horizon and have more than 35 percent clay in the Bt horizon. Ridgecrest soils are calcareous throughout, and lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used mainly for range, but a few areas are dry farmed. Vegetation is bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass, big sagebrush, bitterbrush, snowberry, chokecherry, serviceberry, balsamroot, Oregon grape, and wild sunflower.
DISTRIBUTION AND EXTENT: Southeastern Idaho and adjoining areas. The soils are moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Teton County, Idaho, 1975.
REMARKS: Diagnostic horizons and other features:
Mollic epipedon - 0 to 12 inches
Argillic horizon - 9 to 21 inches