LOCATION COLNEVEE WYEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, frigid Ustic Torriorthents
TYPICAL PEDON: Colnevee silt loam-on a southwest facing slope of 4 percent--cultivated winter wheat. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 5 inches; reddish brown (5YR 5/4) silt loam, dark reddish brown (5YR 3/4) moist; weak fine granular structure; slightly hard, friable, slightly sticky, nonplastic; slightly effervescent, lime is disseminated; moderately alkaline (pH 7.6) clear smooth boundary. (5 to 8 inches thick).
Bw--5 to 8 inches; yellowish red (5YR 4/6) silt loam, dark reddish brown (5YR 3/4) moist; weak medium angular blocky structure; slightly hard, friable, slightly sticky, nonplastic; strongly effervescent, lime is disseminated; moderately alkaline (pH 8.2) gradual smooth boundary. (0 to 5 inches thick)
Bk--8 to 48 inches; reddish yellow (5YR 6/6) silt loam, yellowish red (5YR 4/6) moist; massive; slightly hard, friable, slightly sticky, nonplastic; violently effervescent, common fine and medium, irregularly shaped, segregated seams and soft masses of lime; moderately alkaline (pH 8.4) gradual wavy boundary. (35 to 47 inches thick)
C--48 to 60 inches; reddish yellow (5YR 6/6) silt loam, yellowish red (5YR 4/6) moist; platelets of siltstone; hard, firm, slightly sticky, slightly plastic; siltstone fragments break down upon texturing; violently effervescent, lime disseminated; moderately alkaline (pH 8.4).
TYPE LOCATION: Weston County, Wyoming, 4 miles west of Four Corners, 450 feet south and 80 feet west of the SW1/4 corner of sec. 9, T. 47 N., R. 61 W.
RANGE IN CHARACTERISTICS: Depth to weathered bedrock is greater than 60 inches. Depth to the Bk horizon ranges from 5 to 13 inches. The mean annual soil temperature is 40 to 46 degrees F., and the mean annual summer temperature is 59 to 65 degrees F. The family textural control section is silt loam, loam, or very fine sandy loam averaging between 10 and 18 percent clay and less than 15 percent fine sand or coarser. The depth to the base of the Bw horizon, when present, is less than 10 inches. Calcium carbonate equivalent is less than 15 percent except in discontinuous pockets or thin strata in the Bk horizon.
The Ap horizon has hue of 5YR through 10YR, value of 4 through 6 dry, 3 or 4 moist, and chroma of 2 through 4. Where the color is as dark or darker than 5.5 dry and 3.5 moist, the horizon has chroma of 4 or is too thin for a mollic epipedon. Texture is typically silt loam, but may be loam. It ranges from neutral through moderately alkaline. Lime is disseminated.
The Bw horizon has hue of 2.5YR through 7.5YR, value of 3 through 5 dry, 3 or 4 moist, and chroma of 4 through 6. Texture is typically silt loam, but may be loam. It is mildly or moderately alkaline. Lime is disseminated. The Bw horizon may be absent in some pedons.
The Bk and C horizons have hues of 2.5YR through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma 3 through 6. Lime is present as many fine and medium, irregularly shaped, segregated seams and soft masses which appear to be the result of in-place weathering with some local segregation. It is mildly or moderately alkaline.
COMPETING SERIES: There are no soils in the same family as
Colnevee. The
Keota,
Mitchell, and
Nevee soils are similar. Keota soils have a yellower hue and have siltstone between depths of 20 and 40 inches. Mitchell soils have yellower hue throughout. The Nevee soils have a longer frost-free season and are mesic.
GEOGRAPHIC SETTING: The Colnevee soils are on nearly level to sloping upland terraces, alluvial fans, and fan aprons. Slopes range from 2 to 15 percent. The Colnevee soils formed in silty alluvium from mixed sources. The average annual temperature is 43 to 45 degrees F., and the average annual precipitation is 15 to 19 inches. Elevation is 4,600 to 6,000 feet. The frost-free season is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Vassett and Colhill soils. The Vassett soils have a mollic epipedon and an argillic horizon. The Colhill soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained, surface runoff is slow to medium on gentle slopes and medium to rapid on sloping areas. Permeability is moderate.
USE AND VEGETATION: These soils are used for rangeland, hayland, and cropland. Winter wheat and alfalfa are the principal crops. Native vegetation consists of western wheatgrass, needleandthread, green needlegrass, and blue grama.
DISTRIBUTION AND EXTENT: Black Hills area of northeast Wyoming. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Weston County, Wyoming; 1983.