LOCATION HYSHAM MT+WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, mesic Aridic Ustifluvents
TYPICAL PEDON: Hysham loam - native grass and shrubs. (Colors are for dry soil unless otherwise noted)
A1--0 to 3 inches; grayish brown (2.5Y 5/2) loam, very dark grayish brown (2.5Y 3/2) moist; vesicular massive crust as uppermost 1/2 inch with weak thin to thick platy structure below; soft, very friable; slight effervescence; strongly alkaline (pH 9.0); abrupt boundary. (1 to 3 inches thick)
B2--3 to 8 inches; light yellowish brown (2.5Y 6/3) loam, olive brown (2.5Y 4/2) and very dark grayish brown (2.5Y 3/2) moist; weak coarse columnar structure; extremely hard, friable, slightly sticky, slightly plastic; column faces have very thin coatings that make them very slippery when wet; insides of columns are slightly sticky and slightly plastic; strong effervescence; very strongly alkaline (pH 9.5); clear boundary. (0 to 5 inches thick)
C1--8 to 12 inches; light yellowish brown (2.5Y 6/3) loam, olive brown (2.5Y 4/3) and very dark grayish brown (2.5Y 3/2) moist; weak coarse blocky structure; very hard, very friable, strong effervescence; very strongly alkaline (pH 9.5). (1 to 4 inches thick)
C2--12 to 60 inches; light yellowish brown (2.5Y 6/3) stratified loam, very fine sandy loam and silt loam; light olive brown (2.5Y 5/3) moist; massive; slightly hard, very friable; strong effervescence; few threads of salt in middle part; very strongly alkaline (pH 9.3).
TYPE LOCATION: Treasure County, Montana; 300 feet east and 100 feet north of SW corner of SE1/4NE1/4 sec. 24, T.6N., R.24E.
RANGE IN CHARACTERISTICS: Hysham soils are usually dry between depths of 4 and 12 inches when soil temperature at a depth of 20 inches is warmer than 41 degrees F. but they are not dry in all parts above 12 inches for more than 1/2 the time during this period. Mean annual soil temperature ranges from 47 degrees to 50 degrees F. Hue is 10YR through 5Y. The materials between depths of 10 to 40 inches are loam or clay loam with 20 to 35 percent clay. The A1 horizon has value of 5 or less dry and 3 or less moist. A thin incipient A2 horizon is present in some pedons. The B2 horizon ranges from weak medium or coarse columnar to weak medium or coarse blocky structure with very hard or extremely hard consistence. In some pedons there are coatings of brown as streaks or bands on the surfaces of the peds. In some pedons there are mycelial segregations of both lime and salts.
COMPETING SERIES: These are the Arvada, Barnum, Bone, Haverson, San Mateo and Vananda series. Arvada and Bone soils have distinct horizonation with albic and natric horizons and have more than 35 percent clay in the control section. Barnum soils have hue of 5YR or 10R in the C horizon. Haverson soils lack very strong alkaline reaction or compact and hard consistence of subsurface horizons and they do not have a crusted surface in cultivated fields. San Mateo soils are moderately alkaline. Vananda soils have more than 35 percent clay.
GEOGRAPHIC SETTING: Hysham soils are on level to sloping alluvial fans and stream terraces. They formed in calcareous, very strongly alkaline alluvial of mixed mineral origin. The climate is cool semiarid with mean annual temperature ranging from 45 degrees to 50 degrees F. and mean annual precipitation ranging from 10 to 14 inches.
PRINCIPAL ASSOCIATED SOILS: These are the Heldt, Lohmiller, and McRae soils and the competing Haverson soils. Heldt soils have more than 35 percent clay in the control section and have less than 15 percent exchangeable sodium in the subsoil. Lohmiller soils are fine textured, light colored soils of the valley bottom lands. McRae soils have cambic horizons and Cca horizons.
DRAINAGE AND PERMEABILITY: Well-drained; slow permeability.
USE AND VEGETATION: Used mainly as native pasture. Some areas are in cultivation, but poor crops reflect the high alkali and salt conditions in the soil. Vegetation is mainly western wheatgrass, Sandberg bluegrass, sagebrush, greasewood, and pricklypear.
DISTRIBUTION AND EXTENT: Moderately extensive in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Treasure County, Montana, 1961.
REMARKS: Hysham soils were formerly classified as Alluvial soils.
OSED scanned by SSQA. Last revised by state on 2/73.