LOCATION COXLAKE WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Cumulic Haploxerolls
TYPICAL PEDON: Coxlake silt loam - on a 1 percent slope at 1,980 feet elevation, under grass-clover pasture. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate medium granular structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine roots; common very fine tubular pores; neutral (pH 6.6); clear wavy boundary. (4 to 10 inches thick)
A--6 to 29 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist, few fine faint brown (7.5YR 5/4) mottles, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine roots; common very fine tubular pores; 5 percent fine pebbles; neutral (pH 6.8); clear wavy boundary. (15 to 35 inches thick)
AC--29 to 38 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; common medium distinct light brown (7.5YR 6/4) mottles, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; few very fine roots; common very fine tubular pores; 10 percent fine pebbles; neutral (pH 6.8); clear wavy boundary (5 to 12 inches thick)
C1--38 to 48 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; common medium distinct light brown (7.5YR 6/4) mottles, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; few very fine roots; common very fine tubular pores; 10 percent pebbles; neutral (pH 6.8); clear wavy boundary. (5 to 22 inches thick)
C2--48 to 60 inches; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 4/3) moist; many medium distinct reddish yellow (7.5YR 6/6) mottles, strong brown (7.5YR 4/6) moist, massive; soft, very friable, slightly sticky, slightly plastic; few very fine roots; common very fine tubular pores; 30 percent pebbles; 10 percent cobbles; neutral (pH 7.0).
TYPE LOCATION: Colville Indian Reservation; Okanogan County, Washington, about 4 miles northwest of the town of Nespelem; 1,700 feet south, 700 feet west of the northeast corner of sec. 2, T. 3k1 N., R. 30 E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 47 to 50 degrees F. These soils are usually moist but are dry in all parts between depths of 8 and 24 inches for 45 to 60 consecutive days following the summer solstice. The mollic epipedon is 20 to 40 inches thick and is mottled with chromas of 2 or less above 30 inches. The particle-size control section is 5 to 15 percent clay and 0 to 15 percent rock fragments by weighted average.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 dry or moist and is mottled. The lower part of the horizon is silt loam, loam, or very fine sandy loam and is 0 to 15 percent pebbles.
The AC horizon has value of 5 or 6 dry, 3 or 4 moist, and chroma of 2 or 3 dry or moist and is mottled. It is silt loam, loam, fine sandy loam or sandy loam and is gravelly in some pedons. It is 0 to 20 percent pebbles.
The C horizon has value of 6 or 7 dry, 4 or 5 moist, and chroma of 2 or 3 dry or moist. It is fine sandy loam, sandy loam, loamy sand, or sand and is gravelly or very gravelly in some pedons. Stratification of textures is comm on. It is 5 to 45 percent rock fragments.
COMPETING SERIES: These are the Endersby, Evans, Leavenworth, Narcisse Pleasant View, Poween (T), and Redola series. Endersby, Evans, Leavenworth, and Patit Creek soils lack mottles in the control section. Narcisse soils are dry for 60 to 80 consecutive days in the moisture control section. Pleasant View soils are calcareous in the lower part of the control section and are mildly or moderately alkaline throughout. Poween soils are moderately or strongly alkaline throughout. Redola soils are calcareous throughout.
GEOGRAPHIC SETTING: Coxlake soils are on low stream terraces and flood plains. Slopes are 0 to 3 percent. These soils formed in alluvium of mixed mineralogy. Elevations range from 1,700 to 2,600 feet. The climate is characterized by warm, dry summers and cool, moist winters. The average annual precipitation is 12 to 16 inches. The mean January temperature is about 24 degrees F., the mean July temperature is about 69 degrees F., and the mean annual temperature is about 47 degrees F. The frost-free season is 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Benco, Benge, Bossburg, and Ralsen (T) soils and the competing Narcisse soils. Benge and Benco soils are well drained and are sandy-skeletal in the lower part of the control section. Bossburt soils are very poorly drained and have a histic epipedon. Ralsen soils are poorly drained and have a mollic epipedon less than 20 inches thick.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained, very slow runoff; moderate permeability.
USE AND VEGETATION: Principal uses are hay and pasture, livestock grazing, watershed, and wildlife habitat. The native vegetation is quaking aspen, mountain alder, paper birch, and scattered ponderosa pine and Douglas-fir with an understory of blue wildrye, northern bedstraw, spreading sweetroot, redosier dogwood, common snowberry, thimbleberry, trailing blackberry, and saskatoon serviceberry.
DISTRIBUTION AND EXTENT: Northcentral Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Colville Indian Reservation; Okanogan County, Washington, 1987.
REMARKS: Diagnostic horizons and features recognized in this soil are a mollic epipedon from the surface to 29 inches. The particle-size control section is the zone from 10 to 40 inches (parts of the A, AC and C1 horizons).