LOCATION WOLFVAR WY+MT

Established Series
Rev. MRL
03/2014

WOLFVAR SERIES

The Wolfvar series consists of very deep, well drained soils that formed in alluvium derived from sedimentary rock overlying outwash deposits. Wolfvar soils are on nearly level to sloping terraces. Slopes are 0 to 9 percent. The mean annual precipitation is about 17 inches, and the mean annual temperature is about 46 degrees F.

TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Calcidic Argiustolls

TYPICAL PEDON: Wolfvar loam-on east facing slope of about 2 percent in native rangeland. (Colors are for dry soil unless otherwise stated.)

A--0 to 2 inches; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine crumb structure; soft, very friable, slightly sticky and plastic; common very fine and fine roots; slightly alkaline (pH 7.8); clear smooth boundary. (2 to 6 inches thick)

Bt--2 to 8 inches; dark yellowish brown (10YR 4/4) clay loam, dark brown (10YR 3/3) moist; strong coarse subangular blocky structure parting to strong medium and fine subangular blocky; hard, firm, sticky and plastic; common very fine and fine roots; many prominent clay films on vertical and horizontal faces of peds; 2 percent limestone pebbles; slightly alkaline (pH 7.6); clear smooth boundary (4 to 8 inches thick)

Btk--8 to 14 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; moderate medium and coarse subangular blocky structure parting to moderate fine subangular blocky; hard, friable, sticky and plastic; few very fine and fine roots; few faint clay films on vertical and horizontal faces of peds; strongly effervescent; calcium carbonate as few fine threads; 2 percent limestone gravel; moderately alkaline (pH 8.4); clear wavy boundary. (3 to 10 inches thick)

Bk--14 to 37 inches; very pale brown (10YR 8/2) gravelly loam, very pale brown (10YR 8/3) moist; weak medium and coarse subangular blocky structure; hard, friable, sticky and slightly plastic; violently effervescent; calcium carbonate disseminated and as coatings 1 to 3 mm. thick on the bottom of rock fragments; 30 percent gravel; moderately alkaline (pH 8.4); gradual wavy boundary. (6 to 25 inches thick)

2C--37 to 93 inches; very pale brown (10YR 8/2) extremely gravelly loamy sand with few thin strata of silt loam very pale brown (10YR 8/3) moist; loose; nonsticky and nonplastic; strongly effervescent; calcium carbonate as few distinct coatings on the bottom of rock fragments; 70 percent gravel; moderately alkaline (pH 8.4).

TYPE LOCATION: Sheridan County, Wyoming; NW1/4, NE1/4 of sec. 7, T. 55 N., R. 84 W.

RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 14 inches thick. Depth to strongly contrasting material
ranges from 20 to 40 inches. The mean annual soil temperature ranges from 47 to 51 degrees F. Depth to the base of the argillic horizon ranges from 10 to 18 inches. The upper part of the partical-size control sections averages 20 to 35 percent clay. The lower part has 35 to 70 percent gravel and 0 to 10 percent cobbles.

The A horizon has hue of 10YR or 2.5Y, value of 3 through 5 dry, 2 or 3 moist, and chroma of 2 or 3 moist and 2 through 4 dry. Coarse fragments are less than 15 percent gravel. Reaction is neutral through moderately alkaline.

The Bt horizon has hue of 10YR or 2.5Y, value of 3 through 5 dry, 2 or 3 moist, and chroma of 2 or 3 moist and 2 through 4 dry. Texture is heavy clay loam or clay with 35 to 50 percent clay. Coarse fragments range from 0 to 15 percent gravel. Reaction is neutral through moderately alkaline.

The Btk horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 4. Texture is clay loam or clay with 35 to 50 percent clay. Coarse fragments range from 0 to 15 percent gravel. Calcium carbonate equivalent ranges from 8 to 20 percent. Reaction is moderately alkaline or strongly alkaline.

The Bk horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 6 through 8 dry, 5 through 8 moist; and chroma of 2 through 4. Matrix texture is clay loam, sandy loam, loam, or silt loam with 18 to 35 percent clay. Coarse fragments range from 0 to 35 percent gravel. Calcium carbonate equivalence ranges from 15 to 35 percent. Reaction is moderately alkaline or strongly alkaline.

The 2C or 2Bk horizon has hue the color of various sand grains. Texture is very or extremely gravelly sand, loamy sand, or coarse sand. Coarse fragments range from 35 to 70 percent gravel and 0 to 10 percent cobbles. Calcium carbonate content decreases with depth.

COMPETING SERIES: These are the Altvan, Atencio, Eckley, Gustspring, Landavaso, Newlin, Redridge, Tuthill, and Wheatridge series. All these soils have less than 35 percent clay in the argillic horizon. Also the Eckley soils have the contrasting strata above 20 inches. The Newlin, Redridge, and Wheatridge soils are noncalcareous above 40 inches.

GEOGRAPHIC SETTING: Wolfvar soils are on nearly level to sloping terraces. Slopes are simple and range from 0 to 9 percent. The soils formed in alluvium over outwash materials. Elevations are 3,500 to 4,700 feet. The mean annual precipitation ranges from 15 to 19 inches with most occurring during spring and summer. The frost-free season is about 110 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Nunn and the Platner, Wolf, and Nihill soils. Platner soils have abrupt textural changes and lack gravel above 20 inches. Wolf soils have less than 35 percent clay. Nihill soils lack argillic horizons.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.

USE AND VEGETATION: Irrigated and dry cropland, rangeland, and wildlife habitat. Native vegetation is western wheatgrass, prairie junegrass, Idaho fescue, needleandthread, silver sagebrush, and big sagebrush. The main crop is hay.

DISTRIBUTION AND EXTENT: Northeastern Wyoming. The series is of minor extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES ESTABLISHED: Sheridan County Area, Wyoming; 1987.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - 0 to 8 inches (Ap,Bt)

Argillic horizon - 2 to 14 inches (Bt,Btk)

Calcic horizon - 8 to 37 inches (Btk,Bk)

Lithologic discontinuity - 37 inches (2C)

SIR - WY0707

National Cooperative Soil Survey
U.S.A.