LOCATION GOSHAWK WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Andic Haploxeralfs
TYPICAL PEDON: Goshawk gravelly ashy sandy loam, on a north-facing 40 percent slope at 3,900 feet elevation in a Douglas-fir and ponderosa pine forest. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
Oe--0 to 1 inch; moderately decomposed needles and twigs; abrupt smooth boundary. (1 to 3 inches thick)
A--1 to 10 inches; brown (10YR 5/3) gravelly ashy sandy loam, dark yellowish brown (10YR 3/4) moist; moderate fine and medium subangular blocky breaking to moderate fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, fine and large roots; many very fine irregular pores; 15 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (3 to 9 inches thick)
Bw--10 to 15 inches; brown (7.5YR 5/4) gravelly ashy sandy loam, dark brown (7.5YR 3/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic and moderately smeary; common very fine, fine and large roots; many very fine irregular pores; 15 percent gravel; moderately acid (pH 5.8); gradual smooth boundary. (4 to 10 inches thick)
2Bt1--15 to 21 inches; brown (10YR 5/3) extremely gravelly loam, brown (10YR 4/3) moist; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and large roots; many very fine irregular, and common very fine vesicular and tubular pores; common discontinuous faint clay films on faces of peds and in pores; 60 percent gravel and 10 percent cobbles; moderately acid (pH 5.8); clear smooth boundary.
2Bt2--21 to 28 inches; brown (10YR 5/3) extremely gravelly loam, brown (10YR 4/3) moist; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine irregular, and common very fine vesicular and tubular pores; few discontinuous faint clay films on faces of peds and in pores; 70 percent gravel and 10 percent cobbles; moderately acid (pH 5.8); abrupt smooth boundary.
2R--28 inches; fractured andesite.
TYPE LOCATION: Okanogan County, Washington; 9 miles north of Winthrop, Washington; 600 feet east and 1,600 feet south of the northwest corner of section 21, T. 36 N., R. 21 E. (Latitude 48 degrees 36' 33"N., Longitude 120 degrees 13' 39"W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 42 to 45 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 60 to 75 days following the summer solstice. The volcanic ash ranges from 7 to 14 inches thick, and has a estimated moist bulk density of 0.75 to 0.90 g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 1.0 to 2.0 percent, 15-bar water retention of 8 to 12 percent for air dried samples. Depth to bedrock is 20 to 40 inches. The particle-size control section averages from 40 to 70 percent rock fragments, and 12 to 20 percent clay.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 dry or moist.
The Bw horizon has hue of 7.5YR or 10YR, value of 4 to 6 dry, 3 to 5 moist, and chroma of 3 or 4 dry or moist. It is gravelly ashy loam or gravelly ashy sandy loam. It has 15 to 25 percent gravel and 0 to 5 percent cobbles. Reaction is moderately acid to slightly acid.
The 2Bt horizon has value of 4 to 6 dry, 3 to 5 moist, and chroma of 3 or 4 dry or moist. It is extremely gravelly loam, very gravelly loam or very gravelly sandy loam. It has 30 to 80 percent gravel and 5 to 30 percent cobbles. Reaction is moderately acid to slightly acid.
COMPETING SERIES: These are the Mcdanielake, Rendovy (T), and Satus series. Satus soils have hues of 2.5YR to 7.5YR in the 2Bt horizon. Mcdanielake and Rendovy soils are very deep.
GEOGRAPHIC SETTING: Goshawk soils are on shoulders and upper backslopes of mountains at elevations of 3,500 to 5,200 feet. Slopes are 35 to 65 percent. These soils formed in colluvium and residuum from sedimentary and volcanic rock, mixed with a component of glacial till, and a mantle of volcanic ash 7 to 14 inches thick. The climate is characterized by warm, dry summers and cool, moist winters. The average annual precipitation ranges from 20 to 24 inches. The average January temperature ranges from 22 to 26 degrees F., the average July temperature ranges from 62 to 67 degrees F., and the average annual temperature ranges from 40 to 44 degrees F. The frost-free season ranges from 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nicmar and Sandtop soils. Santop soils are on shoulders and upper backslopes and are vitrandic. Nicmar soils are on backslopes and footslopes of mountains and are 60 inches or more to bedrock.
DRAINAGE AND PERMEABILITY: Well drained, rapid runoff; moderate to moderately rapid permeability.
USE AND VEGETATION: This soil is used for timber production, recreation, wildlife habitat, watershed and livestock grazing. Native vegetation is Douglas-fir and ponderosa pine with an understory of Scouler willow, common snowberry, heartleaf arnica, pinegrass, shinyleaf spirea, silky lupine, and pachystima.
DISTRIBUTION AND EXTENT: Okanogan County, Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Okanogan National Forest, Okanogan County, Washington, 2005.
REMARKS: Diagnostic horizons and features in this pedon include:
Ochric epipedon -
Cambic horizon - 10 to 15 inches (Bw horizon)
Argillic horizon - 15 to 28 inches (Bt1 and Bt2 horizons)
PSCS - 15 to 28 inches (Bt1 and Bt2 horizons)