LOCATION SNILEC WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Palexeralfs
TYPICAL PEDON: Snilec ashy sandy loam - forested, on a 36 percent north-facing slope at 2,700 feet elevation. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to1 inch; slightly decomposed forest litter mixed with a small amount of 1980 Mt. St. Helens volcanic ash. (1 to 2 inches thick)
A--1 to 5 inches; light brownish gray (10YR 6/2) ashy sandy loam, dark brown (10YR 3/3) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; common very fine and fine irregular pores; 5 percent gravel; NaF pH 9.6; neutral (pH 7.0); gradual smooth boundary. (2 to 7 inches thick)
AB--5 to 10 inches; light gray (10YR 7/2) gravelly ashy sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure parting to weak fine subangular blocky; soft, very friable, nonsticky and nonplastic; common very fine, fine and medium and few coarse roots; many very fine and fine irregular pores; 10 percent gravel and 5 percent cobbles; NaF pH 9.6; neutral (pH 7.0); gradual smooth boundary. (2 to 5 inches thick)
2Bt1--10 to 18 inches; light brownish gray (10YR 6/2) very cobbly loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure parting to moderate fine subangular; soft, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; few fine and very fine tubular pores; common faint brown (10YR 4/3) clay films lining pores and on faces of peds; 20 percent gravel and 15 cobbles; neutral (pH 7.0); gradual smooth boundary.
2Bt2--18 to 37 inches; light brownish gray (10YR 6/2) very gravelly loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; soft, very friable, slightly sticky and slightly plastic; common fine and medium roots; common fine and very fine tubular pores; common faint brown (10YR 4/3) clay films lining pores and on faces of peds; 30 percent gravel and 10 percent cobbles; neutral (pH 7.0) gradual smooth boundary.
2Bt3--37 to 53 inches; grayish brown (10YR 5/2) very cobbly loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; common fine and very fine tubular pores; common faint brown (10YR 4/3) clay films lining pores and on faces of peds; 35 percent gravel and 20 percent cobbles; neutral (pH 7.2) gradual smooth boundary.
2Bt4--53 to 61 inches; pale brown (10YR 6/3) extremely cobbly loam, brown (10YR 4/3) moist; moderate coarse subangular blocky structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; common fine and very fine tubular pores; common faint brown (10YR 4/3) clay films lining pores and on faces of peds; 35 percent gravel, 30 percent cobbles and 5 percent stones; neutral (pH 7.2).
TYPE LOCATION: Yakima County, Washington; about 8 miles southeast of Cliffdell; about 1,500 feet north, and 2,150 feet east of the southwest corner of section 31, T. 16 N., R. 15 E.; Latitude 46 degrees, 52 minutes, 11 seconds N. and Longitude 120 degrees, 59 minutes, 57 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 44 to 46 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 60 to 75 consecutive days following the summer solstice. Thickness of mixed ash mantle ranges from 7 to 14 inches. These layers have estimated moist bulk density of 0.85 to 1.15 g/cc, glass content of 20 to 35 percent, acid-oxalate extractable aluminum plus one-half of acid-oxalate extractable iron of 0.5 to 1.10, phosphate retention of 25 to 40 percent and 15-bar water retention of 8 to 12 percent for air dried samples. The particle-size control section averages 18 to 27 percent clay and 35 to 60 percent rock fragments.
The A horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist.
The 2Bt horizon has value of 5 to 7 dry, 4 or 5 moist and chroma of 3 or 4 dry or moist. Texture is very cobbly loam, extremely cobbly loam, very gravelly loam, extremely gravelly loam or very gravelly fine sandy loam. Rock fragments range from 35 to 70 percent.
COMPETING SERIES: This is the Jumpmore and Siegel series. Jumpmore soils are dry for 45 to 60 consecutive days following the summer solstice. Siegel soils are dominated by rounded rock fragments of glacial till origin and have 5 to 20 percent glass in the upper 7 to 18 inches.
GEOGRAPHIC SETTING: Snilec soils are on mountain side slopes at elevations of 2,200 to 4,600 feet. These soils formed in colluvium from conglomerate and tuffs from Ellensburg formation materials with a mixed mantle of volcanic ash. Slope is 10 to 70 percent. Climate is characterized by warm, dry summers and cool, moist winters. The mean annual precipitation is 30 to 45 inches. The average January temperature is about 26 degrees F. and the average July temperature is about 62 degrees F. The mean annual temperature is 43 to 45 degrees F. The frost-free season is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nile and Seeburg soils. Nile and Seeburg soils are on mountain side slopes and ridgetops and do not have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained, slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for timber production, wildlife habitat and recreation. Native vegetation is grand fir, Douglas fir, western white pine and western larch with an understory of Oregon grape, pinegrass and elk sedge.
DISTRIBUTION AND EXTENT: Yakima County, Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wenatchee National Forest, Naches Area; Yakima County, Washington, 2003.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - the zone from 1 to 10 inches (A and AB horizons)
Vitrandic soil properties - the zone from 1 to 10 inches (A and AB horizons)
Argillic horizon - the zone from 10 to 61 inches (2Bt1, 2Bt2, 2Bt3, 2Bt4 horizons)
PSCS - the zone from 10 to 30 inches (2Bt1 and part of the 2Bt2 horizons)
Depths to diagnostic horizons and features are measured from the top of the first mineral layer.
The classification of this series has been revised as of 2/01 from Vitrandic Haploxeralfs to Vitrandic Palexeralfs based on no 20 percent decrease in clay from the maximum to a depth of 60 inches.