LOCATION DIPMAN WY+IDEstablished Series
TAXONOMIC CLASS: Clayey over loamy-skeletal, smectitic over mixed, superactive Typic Cryaquolls
TYPICAL PEDON: Dipman clay, meadow. (Colors are for dry soil otherwise noted.)
A--0 to 7 inches; dark gray (10YR 4/1) clay, black (10YR 2/1) moist; weak coarse subangular blocky structure that parts to moderate medium granular; hard, friable, very plastic; 5 percent gravel; slightly alkaline (pH 7.4); gradual wavy boundary. (4 to 12 inches thick)
Ag--7 to 16 inches; reddish gray (5YR 5/2) clay, dark reddish brown (5YR 3/2) moist; weak coarse prismatic structure that parts to moderate medium subangular blocky; extremely hard, very plastic; common medium distinct light gray (2.5Y 7/1) moist redox depletions, and brown (10YR 4/3) moist redox concentrations; 10 percent gravel and cobble; slightly alkaline (pH 7.4); gradual wavy boundary. (6 to 15 inches thick)
Bg1--16 to 34 inches; reddish gray (5YR 5/2) light clay, dark reddish gray (5YR 4/2) moist; weak coarse subangular blocky structure; hard, friable; many large distinct dark gray (2.5Y 4/1) moist redox depletions and brown (10YR 4/3) moist redox concentrations; 10 percent gravel and cobble; slightly alkaline (pH 7.4); gradual wavy boundary. (10 to 20 inches thick)
2Bg2--34 to 60 inches; reddish gray (5YR 5/2) very gravelly loam, dark reddish gray (5YR 4/2) moist; many large distinct dark gray (2.5Y 4/1) moist redox depletions and brown (10YR 4/3) moist redox concentrations; weak coarse subangular blocky structure; hard, friable; 60 percent gravel and cobble; slightly alkaline (pH 7.4).
TYPE LOCATION: Lincoln County, Wyoming; near the center of the northwest 1/4 of section 15, T.32N., R.119W.
RANGE IN CHARACTERISTICS: The mollic epipedon is 7 to 19 inches thick. Depth to gravelly loam or light clay loam materials is 26 to 40 inches. These soils are typically noncalcareous for more than 60 inches but some pedons are calcareous between 40 and 60 inches. The solum is 26 to more than 40 inches thick and depth to bedrock is more than 40 inches. Typically, these soils have redox features in the lower part of the mollic epipedon but have redox features near the surface in some pedons. The content of organic carbon in the mollic epipedon normally ranges from 1 to about 5 percent. Thin organic horizons are present in some pedons. Cation exchange capacity is 60 to 90 milliequivalents per 100 grams of clay. Content of coarse fragments ranges from 0 to 15 percent in the upper part of the solum and from 35 to 75 percent in the lower part. The control section averages heavy clay loam to light clay with 35 to 50 percent clay, 20 to 50 percent silt, and 10 to 40 percent sand. Mean annual soil temperature is 33 degrees to 47 degrees F. and mean summer soil temperature is 40 degrees to 58 degrees F. Soil temperatures are usually controlled by the temperature of the groundwater table that lies at or near the surface during part of most seasons. The A horizon has hue of 10YR through 5YR, value of 4 or 5 dry and 2 or 3 moist, and chroma of 0 through 2. Common medium distinct to many large prominent redox features occur throughout the A horizon in some pedons but normally are confined to the lower half. Primary structure is usually granular but is subangular blocky in some pedons. This horizon is soft to slightly hard and neutral to slightly alkaline. The Bg horizon has hue of 5YR or 2.5YR, value of 5 or 6 dry and 4 or 5 moist, and chroma of 1 or 2. It has common medium distinct to many large prominent redox features. It usually has subangular blocky primary structure but the horizon may be massive in some pedons. Coarse fragments increases with depth and exceed 35 percent between depths of 26 and 40 inches.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Dipman soils are on nearly level to gently sloping alluvial fans, terraces, and flood plains. These soils formed in moderately fine to fine textured, noncalcareous, reddish brown parent material derived from red beds and intermixed with quartzitic alluvial gravel and cobble. Slopes range from 0 to about 6 percent. At the type location the average annual precipitation is 20 inches with nearly equal amounts of precipitation occurring in all months. The average annual temperature is 39 degrees F., average summer temperature is 58 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Narrows and Mundos soils. Narrows soils have calcic horizons. Mundos soils have fine-loamy control sections.
DRAINAGE AND PERMEABILITY: Somewhat poorly or poorly drained; slow runoff; slow permeability. A fluctuating water table occurs at or near the surface of these soils in some seasons.
USE AND VEGETATION: These soils are used principally for native hay meadows. They are tilled to hay crops in some localities where drainage will permit. Principal native vegetation is timothy, native bluegrass, and water tolerant species.
DISTRIBUTION AND EXTENT: Present known distribution limited to the high mountain valleys of Wyoming and Idaho. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Star Valley Area, Idaho and Wyoming, 1971.