LOCATION SKIPEAK            WA
Established Series
Rev. CSN/RJE/TLA/SBC
08/2007

SKIPEAK SERIES


The Skipeak series consists of very deep, somewhat excessively drained soils formed in volcanic ash overlying glacial outwash sands and gravels. Skipeak soils are on terraces at elevations of 1,800 to 2,500 feet. Slopes are 5 to 30 percent. Average annual precipitation is about 80 inches. Mean annual temperature is about 41 degrees F.

TAXONOMIC CLASS: Ashy-skeletal over sandy or sandy-skeletal, amorphic over isotic Andic Haplocryods

TYPICAL PEDON: Skipeak gravelly ashy sandy loam--under a coniferous forest on a 15 percent northwest facing slope at an elevation of 2,060 feet. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures)

Oi--0 to 1 inch; slightly decomposed forest litter.

Oe--1 to 2 inches; moderately decomposed forest litter.

E--2 to 4 inches; pinkish gray (7.5YR 6/2) ashy loamy fine sand, brown (7.5YR 5/2) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic, nonsmeary; common very fine, fine, medium and coarse roots; few fine tubular pores; 5 percent pebbles; NaF pH 9.6; strongly acid (pH 5.2); abrupt wavy boundary. (1 to 4 inches thick)

Bs1--4 to 9 inches; brown (7.5YR 4/4) gravelly ashy sandy loam, dark brown (7.5YR 3/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic, weakly smeary; common very fine and few medium and coarse roots; few fine tubular pores; 20 percent pebbles; NaF pH 11.5; strongly acid (pH 5.4); gradual wavy boundary. (3 to 10 inches thick)

Bs2--9 to 19 inches; strong brown (7.5YR 5/6) very gravelly ashy sandy loam, strong brown (7.5YR 4/6) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic, weakly smeary; common very fine and fine, few medium roots; few fine tubular pores; 30 percent pebbles and 5 percent cobbles; NaF pH 11.5; moderately acid (pH 5.8); gradual wavy boundary. (8 to 16 inches thick)

2CB--19 to 32 inches; light yellowish brown (10YR 6/4) very gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few fine and medium roots; 35 percent pebbles and 5 percent cobbles; NaF pH 11.5; slightly acid (pH 6.4); clear wavy boundary. (10 to 15 inches thick)

2C--32 to 62 inches; pale yellow (2.5Y 7/4) very gravelly loamy sand, light olive brown (2.5Y 5/4) moist; single grain; loose, nonsticky and nonplastic; few fine and medium roots; 40 percent pebbles and 10 percent cobbles; NaF pH 11.0; slightly acid (pH 6.4).

TYPE LOCATION: Chelan County, Washington; about 12 miles northwest of Stehekin; 1,000 feet west and 500 feet south of northeast corner of sec. 16, T. 33 N., R. 16 E.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 40 to 42 degrees F. The soils are usually moist, but are dry in the soil moisture control section for 30 to 45 days during summer and fall. The upper 14 to 30 inches of the soil has an estimated moist bulk density of 0.70 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 more than 2.0 percent and 15-bar water retention of 5 to 12 percent for air dried samples. The upper portion of the particle-size control section averages 35 to 40 percent rock fragments by volume. The lower portion of the particle-size control section contains 50 to 60 percent rock fragments. Depth to the lithologic discontinuity is 14 to 30 inches.

The E horizon has hue of 7.5YR or 10YR, value of 5 or 6 dry, 3 through 5 moist, and chroma of 0 through 2 moist or dry. Rock fragments range from 0 to 10 percent. Reaction is strongly acid or moderately acid.

The Bs horizons have value of 5 or 6 dry, 3 or 4 moist, and chroma of 4 through 6 dry. Textures are gravelly ashy sandy loam, very gravelly ashy sandy loam or very gravelly ashy loam. Rock fragments range from 15 to 40 percent by volume. Reaction is strongly acid or moderately acid.

The 2CB and 2C horizons have hue of 10YR or 2.5Y, value of 5 through 7 dry, 3 through 5 moist, and chroma of 4 through 6 moist or dry. Textures are very gravelly loamy sand or very gravelly sand. Rock fragments range from 45 to 60 percent by volume. Structure is weak fine subangular blocky to single grain. Reaction is slightly acid or neutral.

COMPETING SERIES: These are the Altapeak, Index and Serene series. Altapeak soils are on mountains and have a paralithic contact at 40 to 60 inches. Serene soils are 20 to 40 inches deep to a paralithic contact and have a 7 to 14 inch thick ash mantle. Index soils have a paralithic contact at 40 to 70 inches and are on mountains.

GEOGRAPHIC SETTING: Skipeak soils are on terraces at elevations of 1,800 to 2,500 feet. Slopes are 5 to 30 percent. These soils formed in volcanic ash overlying glacial outwash sands and gravels. They are in a climate with warm, dry summers and cold, moist winters. The average annual precipitation is 70 to 100 inches. The mean January temperature is about 22 degrees F, the July temperature is about 59 degrees F, and the mean annual temperature is about 41 degrees F. The growing season at 28 degrees F is about 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Saska and Gilpar soils. Saska soils are ashy over loamy-skeletal. Gilpar soils are loamy-skeletal.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained, slow to medium runoff; rapid permeability.

USE AND VEGETATION: Used for woodland, wildlife habitat, watershed, and recreation. Vegetation is lodgepole pine, western white pine and Douglas-fir with an understory of pachystima, huckleberry, longtube twinflower and princess pine.

DISTRIBUTION AND EXTENT: East slopes of the Cascade Mountains in northern Chelan County. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Chelan County, Washington, 1995.

REMARKS: Diagnostic horizons and features recognized in this pedon are an albic horizon from 2 to 4 inches, a spodic horizon from 4 to 19 inches, and a lithologic discontinuity at 19 inches. The particle-size class was updated to ashy-skeletal over sandy or sandy-skeletal on 8/2007 due to addition of this class in the 10th edition of Keys to Soil Taxonomy.


National Cooperative Soil Survey
U.S.A.