LOCATION SNOWPLOW WAEstablished Series
TAXONOMIC CLASS: Ashy, mixed Humic Xeric Vitricryands
TYPICAL PEDON: Snowplow ashy fine sandy loam - forestland, on an 8 percent east-facing slope at an elevation of 5,800 feet. (Colors are for dry soil unless otherwise noted. All textures are apparent field textures.)
Oi--0 to 2 inches; slightly decomposed needles and twigs mixed with a small amount of 1980 Mt. St. Helens volcanic ash. (1 to 3 inches thick.)
A1--2 to 6 inches; brown (10YR 5/3) ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, common medium, and few coarse roots; many very fine and fine irregular pores; 10 percent gravel; NaF pH 9.9; moderately acid (pH 5.6); clear smooth boundary. (3 to 6 inches thick)
A2--6 to 12 inches; brown (10YR 5/3) ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, and common fine and medium roots; many very fine and fine irregular pores; 10 percent gravel; NaF pH 9.9; strongly acid (pH 5.5); gradual smooth boundary. (4 to 8 inches thick)
AB--12 to 18 inches; brown (10YR 5/3) ashy fine sandy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine, and few medium and coarse roots; many very fine and fine irregular pores; 10 percent gravel; NaF pH 10.1; strongly acid (pH 5.5); gradual smooth boundary. (5 to 9 inches thick)
Bw1--18 to 24 inches; light yellowish brown (10YR 6/4) ashy fine sandy loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine, and few medium roots; many very fine and fine irregular pores; 10 percent gravel; NaF pH 10.3; strongly acid (pH 5.3); clear smooth boundary. ( 6 to 8 inches thick)
2Bw2--24 to 36 inches; brown (7.5YR 5/4) very gravelly ashy fine sandy loam, brown (7.5YR 4/4) moist; weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, and few fine and medium roots; many very fine and fine irregular pores; 35 percent gravel; NaF pH 10.3; strongly acid (pH 5.4); gradual smooth boundary.
2Bw3--36 to 46 inches; light brown (7.5YR 6/4) very gravelly ashy fine sandy loam, brown (7.5YR 4/4) moist; weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine, medium and coarse roots; many very fine and fine irregular pores; 50 percent gravel; NaF pH 10.5; moderately acid (pH 5.6); gradual smooth boundary. (Combined thickness of 2Bw horizon is 20 to 30 inches)
3BC--46 to 62 inches; light brown (7.5YR 6/4) very gravelly loam, brown (7.5YR 4/4) moist; weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine, medium and coarse roots; few very fine and fine irregular, and common fine tubular pores; 35 percent gravel; NaF pH 9.0; moderately acid (pH 6.0);
TYPE LOCATION: Yakima County, Washington; about 5 miles northeast of the Tieton Guard Station; about 2,200 feet south and 350 feet west of the northeast corner of section 2, T. 14 N., R. 14 E.; Latitude 46 degrees, 40 minutes, 01 seconds N. and Longitude 121 degrees, 02 minutes, 8 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 41 to 44 degrees F. The estimated mean summer soil temperature is 42 to 46 degrees F. These soils are usually moist but are dry in the moisture control section for 45 to 60 consecutive days following the summer solstice. Thickness of andic soil material ranges from 40 to 60 inches. The andic material has an estimated moist bulk density of 0.75 to 1.00 g/cc, glass content of 10 to 30 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 1 to 2 percent, phosphorus retention of 40 to 60 percent and 15-bar water retention of less than 12 percent for air dried samples. The particle-size control section has 5 to 10 percent rock fragments in the upper part and 35 to 60 percent rock fragments in the lower part. Thickness of the umbric epipedon is 10 to 20 inches.
The Bw1 horizon has hue of 7.5YR or 10YR, value of 5 or 6 dry, 4 or 5 moist and chroma of 2 to 4 dry. Texture is ashy fine sandy loam or ashy sandy loam. It has 5 to 10 percent rock fragments. Reaction is moderately or strongly acid.
The 2Bw horizon has hue of 7.5YR or 10YR, value of 5 or 6 dry, 4 or 5 moist and chroma of 2 to 4 dry. Texture is very gravelly ashy fine sandy loam, very gravelly ashy sandy loam or very cobbly ashy sandy loam. It has 35 to 60 percent rock fragments. Reaction is moderately or strongly acid.
The BC horizon, when present, is very gravelly loam or gravelly sandy loam. Reaction is moderately or slightly acid.
COMPETING SERIES: There are no competing series in this family. A similar soil in a glassy family is the Cultus (T) series. Cultus soils have 70 to 100 percent glass in the ash mantle and are 40 to 60 inches deep to glacial till.
GEOGRAPHIC SETTING: Snowplow soils formed in volcanic ash over colluvium from basalt or andesite. Snowplow soils are on mountain slopes and ridges. Slopes are 5 to 45 percent. Elevation is 4,300 to 6,300 feet. The average annual precipitation is 40 to 55 inches. The average January temperature is 24 degrees F., the average July temperature is 62 degrees F. and the average annual temperature is 39 to 43 degrees F. The frost-free season is 30 to 60 days. The growing season at 28 degrees F. is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fiscus and Naxing soils. Fiscus soils are on mountain slopes and ridges and are ashy over loamy-skeletal and have an argillic horizon. Naxing soils are on plateaus, benches and side slopes and are ashy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; very slow to rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat and recreation. Native vegetation is subalpine fir, grand fir, lodgepole pine, Engelmann spruce, Douglas-fir and western larch with an understory of elk sedge, big huckleberry, Jacob's ladder, beargrass and princes pine.
DISTRIBUTION AND EXTENT: Eastern slopes of the Cascade Mountains in Yakima County, Washington. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wenatchee National Forest, Naches Area; Yakima County, Washington, 2003. The name is from Snowplow Mountain on the Yakima Indian Reservation, Yakima County, Washington.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Umbric epipedon - 2 to 18 inches (A and AB horizons)
Cambic horizon - 18 to 46 inches (Bw1, 2Bw2, and 2Bw3 horizons)
Andic soil properties - 2 to 46 inches (A1, A2, AB, Bw1, 2Bw2, and 2Bw3)
PSCS - zone from 2 to 42 inches (A1, A2, AB, Bw1, 2Bw2, and part of the 2Bw3 horizons) with 2 to 24 inches meeting ashy family and 24 to 42 inches meeting ashy-skeletal family. The family is based on a weighted average of 23 percent rock fragments and meets ashy family.
Depths to diagnostic horizons and features are measured from the top of the first mineral layer.
ADDITIONAL DATA: Complete laboratory data is available for this soil. NSSL pedon number 92P 17