LOCATION BOWBAC WY+MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ustic Haplargids
TYPICAL PEDON: Bowbac sandy loam-on a northeast facing slope of 1 percent under native vegetation. (Colors are for dry soil unless otherwise stated.)
A--0 to 3 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak fine and very fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine roots; neutral (pH 6.8); abrupt wavy boundary. (2 to 7 inches thick)
Bt1--3 to 25 inches; yellowish brown (10YR 5/4) sandy clay loam, brown (10YR 4/3) moist; moderate coarse and medium prismatic structure parting to moderate medium and coarse angular blocky; hard, friable, slightly sticky and moderately plastic; common fine and very fine, few medium and coarse roots; many distinct clay films on faces of peds; neutral (pH 7.2); clear wavy boundary. (8 to 24 inches thick)
Bt2--25 to 31 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium fine and very fine roots; common distinct clay films on faces of peds; slightly alkaline (pH 7.6); clear wavy boundary. (4 to 8 inches thick)
Bk--31 to 39 inches; very pale brown (10YR 7/3) sandy loam, brown (10YR 5/3) moist; massive; soft, friable, slightly plastic; few medium, fine and very fine roots; slight effervescence, calcium carbonate as few fine and medium soft masses; moderately alkaline (pH 8.0); abrupt smooth boundary. (6 to 18 inches thick)
Cr--39 inches; slightly hard, slightly effervescent, argillaceous sandstone.
TYPE LOCATION: Campbell County, Wyoming; 1250 feet north and 1350 feet west of the southeast corner of sec. 23, T. 42 N., R. 72 W. 43 degrees 35 minutes 45 seconds north latitude and 105 degrees 28 minutes 5 seconds west longitude.
RANGE IN CHARACTERISTICS: Depth to soft sandstone ranges from 20 to 40 inches. Depth to continuous carbonate accumulation ranges from 10 to 35 inches, and depth to the base of the argillic horizon ranges from 10 to 35 inches. Coarse fragments range from 0 to 15 percent and are soft sandstone channers or semirounded gravel. The soil is dry in the moisture control section more than half the time cumulative that the soil temperature at a depth of 20 inches is 41 degrees F. and is never moist in some or all parts for as long as 60 consecutive days when the soil temperature at a depth of 20 inches is 41 degrees F., which occurs about April 21-27, but is dry in all parts of the moisture control section for at least 60 consecutive days from July 15 to October 25 and for at least 90 cumulative days during this period. The mean annual soil temperature is 47 to 53 degrees F., and the soil temperature at a depth of 20 inches is 41 degrees F. or more for 175 to 192 days. EC ranges from 0 to 2 mmhos throughout the profile.
The A horizon has hue of 2.5Y through 7.5YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 4. Textures are loamy fine sand, sandy loam, sandy clay loam, fine sandy loam, very fine sandy loam, or loam. Reaction is typically neutral or slightly alkaline but ranges to moderately alkaline in some pedons.
The Bt horizon has hue of 2.5Y through 7.5YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 4. In pedons where mollic colors are present in this horizon, the layer is too thin to meet the requirements for a mollic epipedon. Texture is sandy clay loam with more than 35 percent fine sand or coarser. Clay ranges from 20 to 35 percent. Reaction is typically slightly alkaline but may range from neutral to moderately alkaline.
Some pedons have a Btk horizon.
The Bk horizon has hue of 2.5Y through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 6. Texture is typically sandy loam or sandy clay loam but may be fine sandy loam or very fine sandy loam. Carbonates range from 6 to 14 percent. This horizon does not meet the requirements of a diagnostic calcic. Discontinuous horizons with greater than 15 percent carbonates occur in some pedons. Reaction is moderately or strongly alkaline with less than 15 percent ESP.
The Cr is a paralithic contact to calcareous, argillaceous sandstone. This material is weakly consolidated and does restrict the movement of water and, therefore, roots. Interbedded shales may be present in some areas and may form the contact.
COMPETING SERIES: These are the Balon, Blancot, Buckle, Cambria, Chilerojo, Chilojo, Cushman, Decolney, Doacum, Forkwood, Fort, Gaddes, Gapbutte(T), Gapmesa, Hagerman, Hagerwest, Hiland, Mentmore, Oelop, Olney, Palacid, Penistaja, Pokeman, Potts, Pugsley, Quagwa, Redpen, Spangler, Sundance, Tamarindo, Teckla, and Yenlo series. Balon, Blancot, Buckle, Cambria, Chilerojo, Chilojo, Decolney, Doacum, Forkwood, Fort, Hiland, Mentmore, Oelop, Olney, Palacid, Penistaja, Potts, Quagwa, Redpen, Sundance, Tamarindo, Teckla, and Yenlo soils lack bedrock above 40 inches. Cushman soils have less than 35 percent fine sand or coarser in the Bt horizon. Hagerwest, Gaddes, Gapbutte, Gapmesa, and Hagerman soils have a lithic contact at 20 to 40 inches. Pokeman soils have alabaster at 20 to 40 inches and hues redder than 7.5YR throughout. Pugsley and Spangler soils are noncalcareous throughout.
GEOGRAPHIC SETTING: Bowbac soils are on alluvial fans, terraces, dissected fan remnants, fan piedmonts, hillslopes, pediments, plateaus, ridges and buttes. Slopes are 0 to 15 percent. Elevations are 3,500 to 6,500 feet. The average annual precipitation is 13 inches with over half of the annual precipitation falling in April, May, and June and less than one inch falling in each month of July, August, September, and October. Precipitation ranges from 10 to 14 inches. The mean annual temperature ranges from 43 to 51 degrees F. The frost-free season is about 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Cushman, Hiland, and Cambria soils and the Parmleed soils. Parmleed soils have over 35 percent clay in the Bt horizon.
DRAINAGE AND PERMEABILITY: Well drained; runoff is medium or low; moderate permeability.
USE AND VEGETATION: These soils are used primarily for grazing. Native vegetation is needleandthread grass, blue grama, western wheatgrass, and big sagebrush.
DISTRIBUTION AND EXTENT: Central and northern Wyoming. The soil is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Carbon County, Montana; 1971.
REMARKS:Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 3 inches (A)
Argillic horizon - 3 to 31 inches (Bt1,Bt2)
Horizon of secondary calcium carbonate accumulation - 31 to 39 inches (Bk)
Paralithic contact - 39 inches (Cr)
SIR - WY1133
LRR - G