LOCATION COCOLALLA WAEstablished Series
TAXONOMIC CLASS: Ashy, glassy, mesic Aquandic Endoaquolls
TYPICAL PEDON: Cocolalla silty clay loam - cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 5 inches; gray (10YR 5/1) silty clay loam, black (10YR 2/1) moist; moderate medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine pores; neutral (pH 7.0); clear smooth boundary. (5 to 7 inches thick)
A12--5 to 14 inches; gray (10YR 5/1) silty clay loam, black (10YR 2/1) moist; moderate thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine pores; mildly alkaline (pH 7.4); abrupt smooth boundary. (0 to 9 inches thick)
C1g--14 to 20 inches; light gray (10YR 7/1) silt loam, dark gray (10YR 4/1) moist; moderate thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and fine pores; few coarse krotovinas 1 to 2 inches in diameter; mildly alkaline (pH 7.6); clear smooth boundary. (6 to 8 inches thick)
C2g--20 to 26 inches; light gray (10YR 7/1) silt loam, dark gray (10YR 4/1) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine pores; few coarse krotovinas 1 to 2 inches in diameter; mildly alkaline (pH 7.6); clear wavy boundary. (4 to 8 inches thick)
C3g--26 to 46 inches; white (2.5Y 8/2) silt loam, light brownish gray (10YR 6/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; few very fine and fine tubular pores; few coarse distinct yellowish brown (10YR 5/4) mottles on cleavage faces and in pores; mildly alkaline (pH 7.6); abrupt smooth boundary. (18 to 22 inches thick)
C4g--46 to 56 inches; light gray (2.5Y 7/2) silty clay loam, very dark gray (10YR 3/1) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine tubular pores; few coarse faint light yellowish brown (10YR 6/4) mottles; mildly alkaline (pH 7.6); clear wavy boundary. (8 to 12 inches thick)
C5g--56 to 62 inches; white (N 8/0) clay loam, light brownish gray (2.5Y 6/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine tubular pores; few fine distinct yellowish brown (10YR 5/6) mottles; mildly alkaline (pH 7.6).
TYPE LOCATION: Spokane County, Washington; 200 feet north of center and 63 feet west of north-south center line of section 30, T. 23 N., R. 41 E., W.M.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 47 degrees to 49 degrees F. The soils are saturated in the winter and spring. They are neutral or mildly alkaline. Depth to bedrock is more than 40 inches.
The A horizon has value of 3 through 5 dry, 2 or 3 moist. It is silt loam or silty clay loam. Organic matter is 5 to 9 percent and decreases with increasing depth.
The C horizon has hue of 2.5Y or 10YR, value of 5 through 8 dry, 3 through 8 moist, and chroma of 0 through 2 moist or dry. It is stratified and may be silt loam, very fine sandy loam, silty clay loam, or clay loam. Layers of pumicite or diatomite range in thickness from 2 to 15 inches. Mottles range from faint to prominent.
COMPETING SERIES: These are the Tisch and Tulana series. Tisch soils range from slightly acid to strongly acid and have soil temperature of 49 degrees to 52 degrees F. Tulana soils are slightly acid to very strongly acid in the lower part of the profile, have moderately slow permeability, and platy or blocky structure throughout.
GEOGRAPHIC SETTING: These soils are on level to nearly level basins or depressions in the channeled scablands areas. Elevations range from 1,700 to 2,500 feet. The soils formed in alluvium from loess and volcanic ash. The summers are relatively dry and winters are moist and cold. Mean annual precipitation is 14 to 19 inches. Mean January temperature is 28 degrees F.; average July temperature is 66 degrees F.; mean annual temperature is about 47 degrees F.; and the average frost-free season is about 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anders, Benge, Cheney, Roloff, Stratford and Tucannon series. These soils are well drained. Anders, Roloff and Tucannon soils have bedrock at a depth of 20 to 40 inches. Benge, Cheney, Hessetine and Stratford soils have sand and gravel at a depth of 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Poorly drained; very slow runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for cultivation, range, and wildlife. Native vegetation is tufted hairgrass, reed canarygrass, red top sedge, rush, buttercup, and cowparsnip. Cultivated areas are used for small grains, grasses, and legumes.
DISTRIBUTION AND EXTENT: Eastern Washington and western Idaho. The series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Bonner County, Idaho, 1935.
REMARKS: Additional data - Soil survey laboratory, Lincoln, Nebraska, S57 Wash-32-3 (1-8), S57 Wash-32-4 (1-7).