LOCATION TWOLAKES WA
Established Series
Rev. CSM/RWL/KDPL/KH
09/2019
TWOLAKES SERIES
Landscape--mountains
Landform--mountain slopes, ridges
Slope--5 to 65 percent
Parent material--volcanic ash over mudflow and ashflow deposits or colluvium derived from andesite or basalt
Mean annual precipitation--about 1800 mm
Mean annual air temperature--about 4 degrees C
Depth class--deep, very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy-skeletal over loamy-skeletal, amorphic over isotic Ultic Vitricryands
TYPICAL PEDON: Twolakes ashy sandy loam in an area of forestland, on a 45-percent, west-facing slope at an elevation of 1200 m (All textures are apparent field textures.)
Oi--0 to 5 cm; slightly decomposed forest litter mixed with a small amount 1980 Mount St. Helens volcanic ash
C--5 to 8 cm; ashy sandy loam, light gray (10YR 7/1) dry, brown (10YR 5/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; many very fine and fine irregular pores; NaF pH 10.1; moderately acid (pH 6.0); clear smooth boundary
AB--8 to 20 cm; gravelly ashy sandy loam, gray (10YR 6/1) dry, brown (10YR 4/3) moist; weak fine and medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium and coarse roots; many very fine and fine irregular pores; 20 percent gravel and 5 percent cobbles; NaF pH 11.5; slightly acid (pH 6.2); clear smooth boundary
Bw--20 to 46 cm; very gravelly ashy sandy loam, pale brown (10YR 6/3) dry, 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 and coarse roots; many very fine and fine irregular pores; 35 percent gravel and 10 percent cobbles; NaF pH 11.0; slightly acid (pH 6.3); clear smooth boundary
2Bt1--46 to 81 cm; extremely gravelly loam, light yellowish brown (10YR 6/4) dry, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine, fine, medium, and coarse roots; many very fine and fine irregular pores and few fine tubular pores; common distinct brown (10YR 4/3) clay films lining pores and on faces of peds; 45 percent gravel and 20 percent cobbles; NaF pH 10.1; slightly acid (pH 6.2); clear smooth boundary
2Bt2--81 to 124 cm; extremely gravelly loam, light yellowish brown (10YR 6/4) dry, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine, medium, and coarse roots; common very fine and fine irregular pores and few medium and coarse tubular pores; common distinct brown (10YR 4/3) clay films lining pores and on faces of peds; 50 percent gravel and 25 percent cobbles; NaF pH 9.4; slightly acid (6.2 pH); gradual wavy boundary
2Bt3--124 to 168 cm; extremely gravelly loam, light yellowish brown (10YR 6/4) dry, brown (10YR 4/3) moist; weak medium prismatic structure parting to weak fine and medium subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine, medium, and coarse roots; few medium and coarse tubular pores; few faint clay films lining pores and on faces of peds; 45 percent gravel and 25 percent cobbles; slightly acid (pH 6.4)
TYPE LOCATION: Yakima County, Washington, about 19 km northwest of Cliffdell; about 60 m north and 760 m west of the southeast corner of section 2, T. 18 N., R. 12 E.; latitude 47.069496, longitude -121.311183, datum WGS 84 (coordinates estimated from section, township, and range)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3 to 7 degrees C
Summer soil temperature--6 to 7 degrees C
Rock fragment content in andic soil material--35 to 50 percent
Rock fragment content in argillic horizon--40 to 75 percent
Clay content in argillic horizon--18 to 27 percent
Andic soil properties
*Thickness--36 to 65 cm
*Moist bulk density--0.65 to 1.0 g/cm3
*Glass content--30 to 70 percent
*Acid oxalate aluminum plus one-half iron--0.5 to 1.0 percent
*Phosphorus retention--50 to 70 percent
*15-bar water retention (air-dried samples)--8 to 12 percent
Oi horizon
Thickness--3 to 6 cm
C horizon (where present)
Chroma--1 or 2 moist
Thickness--0 to 8 cm
AB horizon
Hue--7.5YR, 10YR
Value--5 or 6 dry, 3 or 4 moist
Chroma--1 to 6 moist
Thickness--3 to 13 cm
Bw horizon
Hue--7.5YR, 10YR
Value--4 or 5 moist
Chroma--2 to 4 moist or dry
Rock fragment content--35 to 60 percent
Thickness--23 to 43 cm
2Bt horizon
Hue--7.5YR, 10YR
Value--4 to 6 dry or moist
Chroma--3 or 4 dry or moist
Rock fragment content--40 to 75 percent
Combined thickness--more than 80 cm
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--1075 to 1825 m
Climate--cool, wet winters; warm, dry summers
Mean annual precipitation--1525 to 2300 mm
Mean January air temperature--about -6 degrees C
Mean July air temperature--about 16 degrees C
Mean annual air temperature--about 3 to 6 degrees C
Frost-free season--35 to 75 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Foggyflat--on benches, plateaus, and side slopes; ashy particle-size class
Ravensroost--on ridges; 50 to 100 cm (moderately deep) to a paralithic contact (andesite)
Walupt--on ridges and mountain slopes; ashy over loamy-skeletal particle-size class
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--high over moderately high
USE AND VEGETATION:
Use--mainly timber production, wildlife habitat, and recreation
Native vegetation--Pacific silver fir, mountain hemlock, subalpine fir, Engelmann spruce, Cascade azalea, big huckleberry, queencup beadlily, beargrass, smooth woodrush
DISTRIBUTION AND EXTENT: Wenatchee National Forest, Naches Area, Kittitas and Yakima Counties, Washington; MLRA 3; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wenatchee National Forest, Yakima County, Washington; 2003
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Argillic horizon--zone from 46 to 157 cm
*Andic soil properties--zone from 5 to 46 cm
*Particle-size control section--zone from 5 to 105 cm
National Cooperative Soil Survey
U.S.A.