LOCATION MUDRAY WYEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Typic Natrargids
TYPICAL PEDON: Mudray sandy loam-rangeland. (Colors are for dry soil unless otherwise stated.)
E--0 to 2 inches; light brown (7.5YR 6/4) sandy loam, brown (7.5YR 5/4) moist; weak thin platy structure parting to moderate fine granular; upper half inch is a vesicular crust; soft, very friable, nonsticky and nonplastic; slightly effervescent, lime disseminated; strongly alkaline (pH 8.9); abrupt smooth boundary. (0 to 4 inches thick)
Btn--2 to 12 inches; reddish brown (5YR 5/3) clay, reddish brown (5YR 4/3) moist; strong coarse columnar structure parting to strong medium angular blocky; very hard, firm, very sticky and plastic; continuous, thin clay films on faces of peds; slightly effervescent, lime as few fine threads on ped faces and disseminated in ped interiors; very strongly alkaline (pH 9.2); gradual wavy boundary. (5 to 14 inches thick)
Bnky--12 to 17 inches; reddish brown (5YR 5/3) sandy clay loam, reddish brown (5YR 4/3) moist; massive; extremely hard, firm, sticky and plastic; violently effervescent, lime as common fine and medium soft masses in seams and as threads; common fine gypsum crystals; very strongly alkaline (pH 9.4); abrupt smooth boundary. (1 to 6 inches thick)
Cr--17 to 60 inches; reddish brown, semiconsolidated sodic shale interbedded with thin lenses of sandstone.
TYPE LOCATION: Fremont County, Wyoming; NE1/4 NE1/4 of sec. 23, T. 4 N., R. 4 E.
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 6 to 20 inches. These soils are typically calcareous throughout due to recharge of the surface but are leached a few inches in some pedons. The mean annual soil temperature ranges from 47 to 53 degrees F. The particle size control section averages clay, silty clay, or heavy clay loam with 35 to 55 percent clay. Soft shale and sandstone fragments range from 0 to 15 percent throughout the whole soil. EC is less than 4 mmhos throughout.
The E horizon has hue of 5Y through 5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. Reaction ranges from mildly alkaline (pH 7.8) through very strongly alkaline (pH 9.6). An A horizon is present in some pedons.
The Btn horizon has hue of 5Y through 2.5YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 4. Texture is typically clay, silty clay, or heavy clay loam with 35 to 55 percent clay, 5 to 45 percent silt, and 15 to 55 percent sand. Reaction is very strongly alkaline. Exchangeable sodium percentage ranges from 15 to 35.
The Bnky horizon has hue of 5Y through 2.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. Texture is sandy clay loam, clay loam, or silty clay loam. Carbonates are segregated and range from 4 to 14 percent. ESP ranges from 12 to 30 percent. Reaction is very strongly alkaline. Gypsum crystals are present in most pedons.
The paralithic contact is at the upper boundary of the Cr horizon. The bedrock consists of sodium saturated shales interbedded with thin strata of sandstone or siltstone. The
upper few inches may be displaced due to frost action.
COMPETING SERIES: These are Effington, Meeteetse, and Youjay soils in similar families. Effington and Meeteetse soils are deep. Youjay soils have frigid temperatures.
GEOGRAPHIC SETTING: Mudray soils are on rock-controlled alluvial fan aprons, hill toeslopes, and backslopes. These soils formed in upslope alluvium weathered from sodic shale. Slopes are 2 to 15 percent. Elevations range from 5,200 to 6,300 feet. The climate is cool, semiarid with moist springs and dry summers. The mean annual precipitation is about 7 inches and ranges from 5 to 9 inches of which about half falls as snow or rain in April, May, and early June. The mean annual temperature is about 43 degrees F. and ranges from 42 to 45 degrees F. Estimated frost-free season is about 110 to 135 days depending upon elevation, aspect, and air drainage.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Effington and Meeteetse soils.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow or medium runoff; very slow permeability.
USE AND VEGETATION; Rangeland and wildlife habitat. Native vegetation consists of Birdfoot sagebrush, bottlebrush squirreltail, bud sagebrush, western wheatgrass, and Gardner saltbush.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
DISTRIBUTION AND EXTENT: Basin areas of central and northwestern Wyoming. The series is of limited extent.
SERIES ESTABLISHED: Fremont County, Wyoming, Riverton Irrigated Area; 1969.