LOCATION YEGEN MT+ND SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Yegen sandy loam, cultivated (colors are for dry soil unless otherwise noted).
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) sandy loam, very dark grayish brown (10YR 3/2) moist; single grained and cloddy tilth; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; neutral; clear boundary. (5 to 8 inches thick)
Bt1--6 to 13 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate medium and coarse prismatic structure parting to weak medium blocky; hard, sticky and plastic; common distinct clay films on faces of peds; neutral (pH 7.3); gradual wavy boundary. (5 to 10 inches thick).
Bt2--13 to 19 inches; pale brown (10YR 6/3) sandy clay loam, brown (10YR 4/3) moist crushed color; prisms are coated dark grayish brown (10YR 4/2) very dark grayish brown (10YR 3/2) moist colors; moderate medium and coarse prismatic structure; hard, friable, sticky and plastic; common very fine roots and tubular pores; common distinct clay films on faces of peds; clay bridging of sand grains with clay film in root channels; neutral; gradual boundary. (10 to 15 inches thick)
Bt3--19 to 28 inches; light olive brown (2.5Y 5/3) sandy clay loam, olive brown (2.5Y 4/3) moist; weak coarse prismatic structure; hard, friable, slightly sticky and slightly plastic; common very fine roots and common very fine tubular pores; common faint clay bridging of sand grains; neutral; clear wavy boundary. (0 to 15 inches thick)
Bk--28 to 34 inches; light yellowish brown (2.5Y 6/3) sandy loam, light olive brown (2.5Y 5/3) moist; weak coarse prismatic structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; common fine threads and masses of lime; strongly effervescent; moderately alkaline; gradual boundary. (6 to 18 inches thick)
BC--34 to 60 inches; light yellowish brown (2.5Y 6/3) sandy loam, light olive brown (2.5Y 5/3) moist; single grained; loose, nonsticky and nonplastic; few very fine roots; disseminated lime; strongly effervescent; moderately alkaline.
TYPE LOCATION: Yellowstone County, Montana; 800 feet south and 720 feet east of the NW corner of sec. 19, T. 2 N., R. 29 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 10 to 16 inches.
A horizon - Hue: 10YR or 2.5Y
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: sandy loam, loam, or fine sandy loam
Clay content: 10 to 27 percent
Reaction: pH 6.1 to 7.3
Bt1 horizon - Hue: 10YR or 2.5Y
Value: 3, 4, or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: sandy clay loam or clay loam
Clay content: 20 to 35 percent
Reaction: pH 6.6 to 8.4
Bt2, Bt3 horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4
Texture: sandy clay loam, clay loam, or sandy loam
Clay content: 15 to 30 percent
Reaction: pH 7.9 to 8.4
Bk horizons - Hue: 2.5Y or 5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 3, 4, or 6
Texture: sandy loam, sandy clay loam
Clay content: 5 to 30 percent
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES: These are the Beartooth (MT), Beeno (WY), Bielenberg (T)(MT), Bookcliff (UT), Bullflat (SD), Cortyzack (CO), Dooley (MT), Empedrado (CO), Fairfield (MT), Farnuf (MT), Felor (SD), Greenway (SD), Gurney (SD), Hangdo (UT), Hyalite (MT), Krem (ND), Lefor (ND), Lininger (CO), Livona (ND), Martinsdale (MT), Maudlin (CO), Moen (CO), Reeder (ND), Sponseller (AZ), Trag (CO), Tschicoma (NM), Ulrant (WY), Vida (MT), Watrous (ND), Wemple (MT), and Williams (ND) series. The Bielenberg soils do not have carbonates above 60 inches. Bookcliff soils have hard sandstone between depths of 40 and 60 inches and the depth to carbonates is 20 inches or less. Bullflat soils have a discontinuity above 40 inches. Cortyzack, Lairfield, Martinsdale, Trag, and Ulrant soils have a calcic horizon. Empedrado and Livona soils are more than 20 inches deep to lime. The Farnuf soils have less than 35 percent sand coarser than very fine sand. Lefor and Greenway soils have a discontinuity in the argillic horizon. Hyalite soils have a skeletal discontinuity above 40 inches. The Gurney, Maudlin, Moen, and Watrous soils have a lithic contact between depths of 20 to 40 inches. The Beeno, Lifor, Lininger, Reeder, and Wemple soils have a paralithic contact between depths of 20 to 40 inches. Hangdo soils have hues redder than 10YR throughout the profile and are mildly or moderately alkaline. Krem soils have a sandy epipedon 20 to 40 inches thick. Sponseller soils have hues redder than 10YR throughout the soil and have less than 45 percent sand in the argillic horizon. Tschicoma soils have rock fragments that are mainly stones to a depth of 40 inches and have argillic horizons that have hues of 7.5YR.
GEOGRAPHIC SETTING: The Yegen soils are on alluvial fans, stream terraces, and sedimentary plains. Elevations are 1,900 to 4,500 feet. Slopes are 0 to 15 percent. These soils formed in thick alluvial or eolian deposits. The climate is characterized by long, cold winters; moist spring; and warm summers. Mean annual precipitation is 13 to 19 inches. Mean annual temperature is 39 to 45 degrees F. The frost-free period is 105 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately permeable.
USE AND VEGETATION: Yegen soils are used mainly for nonirrigated small grains. Potential native vegetation is mainly needleandthread and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Yegen soils are moderately extensive in central and eastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Carbon County (Bridger Area), Montana, 1971.
REMARKS: Soil interpretations records: MT0205, MT0257, and MT1102. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 13 inches (Ap, Bt1 horizon); an argillic horizon from 6 to 28 inches of which the upper 20 inches are the particle-size control section (Bt1, Bt2, Bt3 horizons); a horizon of carbonate accumulation from 28 to 34 inches (Bk horizon). Yegen soils have a frigid temperature regime and an ustic moisture regime.