LOCATION PINRIDGE COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Cumulic Haplustolls
TYPICAL PEDON: Pinridge loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate coarse platy structure; slightly hard, very friable, slightly sticky and slightly plastic; slightly effervescent; mildly alkaline (pH 7.4); clear wavy boundary. (4 to 7 inches thick)
A2--5 to 16 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure parting to weak medium subangular blocky; slightly hard, friable, sticky and plastic; slightly effervescent, mildly alkaline (pH 7.6); clear wavy boundary. (10 to 15 inches thick)
A3--16 to 20 inches; grayish brown (10YR 5/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; 30 percent very coarse platy rock structure and 70 percent weak medium subangular blocky; hard, friable, sticky and plastic; slightly effervescent; mildly alkaline (pH 7.8); clear wavy boundary. (0 to 5 inches thick)
Bk1--20 to 27 inches; 60 percent dark grayish brown (10YR 4/2) and 40 percent pale brown (10YR 6/3) sandy clay loam, very dark grayish brown (10YR 3/2) and brown (10YR 4/3) moist; weak coarse subangular blocky structure; hard, friable, sticky and plastic; strongly effervescent; few fine filaments of calcium carbonate; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 15 inches thick)
Bk2--27 to 41 inches; grayish brown (2.5Y 5/2) sandy clay loam, dark grayish brown (2.5Y 4/2) moist; moderate coarse subangular blocky structure; hard, friable, sticky and plastic; strongly effervescent, common filaments of calcium carbonate; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 20 inches thick)
Bk3--41 to 60 inches; light olive brown (2.5Y 5/4) sandy loam, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure; soft, very friable; slightly sticky and slightly plastic; strongly effervescent, few fine filaments of calcium carbonate; moderately alkaline (pH 8.0).
TYPE LOCATION: Moffat County, Colorado; approximately 5 miles north of Lay, 100 feet north and 700 feet east of the southwest corner of Sec. 32, T. 8 N., R. 93 W. Longitude: 107 degrees, 51 minutes, 50 seconds west; latitude: 40 degrees, 35 minutes, 40 seconds north.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 42 to 45 degrees F., and mean summer soil temperature ranges from 62 to 64 degrees F. The soil moisture control section is moist in all parts for 45 or more consecutive days immediately following April and dry in all parts for 60 or more consecutive days immediately following July 1. Depth to secondary calcium carbonate ranges from 15 to 30 inches. The horizons above the zone of secondary lime accumulation are noneffervescent or slightly effervescent. The mollic epipedon is 16 to 25 inches thick. The particle-size control section is generally free of rock fragments, but thin strata containing up to 15 percent pebbles may occur in some pedons.
The A horizons have hue of 2.5Y or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. Reaction is neutral or mildly alkaline.
The Bk horizons have hue of 2.5Y or 10YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 4. Reaction is mildly alkaline or moderately alkaline. It is sandy clay loam, loam, or clay loam.
The Bk2 or Bk3 horizons have hue of 2.5Y or 10YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 4. Reaction is mildly alkaline or moderately alkaline. It is sandy loam, sandy clay loam, loam, or clay loam. Thin strata of loamy sand may occur in some pedons.
COMPETING SERIES: These are the Brycan (UT), Cordeston (WY), Dalecreek (T)(WY), Enbar (MT), Frolic (NM), Jodero (CO), McGaffey (NM), Nutrioso (AZ), and Straw (MT) series. The Brycan soil has a cambic horizon. Cordeston, Dalecreek, and Frolic soils are noncalcareous above a depth of 40 inches. In addition, Dalecreek soils are moderately well drained. Enbar, Jodero, Nutrioso, and Straw soils are moist in some part of the moisture control section for some period immediately after July 1. McGaffey soils have hues of 7.5YR or redder.
GEOGRAPHIC SETTING: Pinridge soils are on stream terraces and alluvial fans. The soil formed in alluvium derived from sedimentary rocks. Slopes range from 1 to 12 percent. Elevation ranges from 6,400 to 7,200 feet. The mean annual precipitation ranges from 13 to 15 inches. Mean annual temperature ranges from 42 to 45 degrees F. The frost-free period is about 75 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Battlement, Evanston, Forelle, and Rock River soils. Battlement, Forelle, and Rock River soils lack mollic epipedons. Evanston soils have mollic epipedons less than 16 inches thick.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Native vegetation consists of basin wildrye, western wheatgrass, Sandberg bluegrass, rabbitbrush, and basin big sagebrush.
DISTRIBUTION AND EXTENT: Pinridge soils occur in northwestern Colorado. The series is of small extent. Total area is about 3,200 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado, 1991.
REMARKS: The diagnostic horizon recognized in this pedon is the mollic epipedon - the zone from 0 to 20 inches. Last updated by the state 12/90.