LOCATION BURPEAK WAEstablished Series
TAXONOMIC CLASS: Ashy-skeletal over loamy-skeletal, glassy over isotic Xeric Vitricryands
TYPICAL PEDON: Burpeak stony ashy sandy loam, on a northeast facing 65 percent slope at 5,100 feet elevation in a subalpine fir, Engelmann spruce and Douglas-fir forest. (Colors are for dry soil unless other wise stated. All textures are apparent field textures.)
Oe--0 to 2 inches; moderately decomposed needles and twigs; abrupt smooth boundary. (1 to 3 inches thick)
A--2 to 6 inches; pale brown (10YR 6/3) stony ashy sandy loam, brown (10YR 4/3) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic and weakly smeary; many very fine and fine and common medium and coarse roots; common fine irregular pores; 15 percent pebbles, 5 percent cobbles and 10 percent stones; slightly acid (pH 6.4); clear smooth boundary. ( 3 to 5 inches thick)
Bw1--6 to 12 inches; light yellowish brown (10YR 6/4) very cobbly ashy sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic and weakly smeary; many very fine and fine and common medium and coarse roots; common fine and very fine irregular pores; 15 percent pebbles, 25 percent cobbles and 5 percent stones; NaF pH 11.5; slightly acid (pH 6.4); clear smooth boundary.
Bw2--12 to 27 inches; light yellowish brown (10YR 6/4) very cobbly ashy sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic and weakly smeary; many very fine and fine roots; few fine and very fine irregular pores; 25 percent pebbles, 25 percent cobbles and 5 percent stones; NaF pH 11.5; slightly acid (pH 6.2); clear wavy boundary.
Bw3--27 to 34 inches; light yellowish brown (10YR 6/4) very stony ashy sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic and weakly smeary; common very fine and fine roots; few irregular pores; 20 percent pebbles, 20 percent cobbles and 15 percent stones; slightly acid (6.2); gradual wavy boundary. ( combined thickness of the Bw horizon is 22 to 30 inches)
2BC--34 to 47 inches; pale brown (10YR 6/3) very stony sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; few very fine irregular pores; 20 percent pebbles, 15 percent cobbles and 20 percent stones; slightly acid (6.2); gradual wavy boundary. (10 to 16 inches thick)
2R--47 inches; fractured andesite
TYPE LOCATION: Okanogan County, Washington; about 17 miles north of Winthrop, Washington; 2,500 feet east and 1,000 feet north of the southwest corner of section 9, T. 38 N., R. 20 E. (Latitude 48 degrees 46 ' 24"N, Longitude 120 degrees 18' 34"W)
RANGE IN CHARACTERISTICS: The average annual soil temperature at a depth of 20 inches 39 to 43 degrees F. The average annual summer soil temperature ranges from 42 to 46 degrees F. These soil are usually moist but are dry in all parts of the moisture control section for 45 to 60 consecutive days following the summer solstice. Volcanic ash influence is 25 to 35 inches thick. The upper part of the 0 to 40 inch particle size control section has an estimated 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 and 35 to 70 percent rock fragments. The lower part of the particle-size control section has 5 to 12 percent clay and 40 to 80 percent rock fragments. Reaction is slightly acid to moderately acid throughout.
The A horizon has values of 5 or 6 dry, 3 or 4 moist, and chroma of 2 or 3 dry or moist.
The Bw horizon has values of 5 or 6 dry, 3 or 4 moist, and chroma of 3 to 6 dry or moist. It is very cobbly ashy sandy loam, extremely cobbly ashy sandy loam or very stony ashy sandy loam. It has 15 to 25 percent pebbles, 20 to 40 percent cobbles and 5 to 15 percent stones.
The 2BC horizon has values of 4 or 5 dry, 3 or 4 moist, and chroma of 2 to 4 dry or moist. It is very cobbly sandy loam, extremely cobbly sandy loam or very stony sandy loam. It has 15 to 25 percent pebbles, 20 to 40 percent cobbles and 15 to 25 percent stones. Clay content ranges from 5 to 12 percent.
COMPETING SERIES: These are the Azwell, Bagmont, Chewack, Fears, Hallihan, Naxing, Saydab, Tiptop, Wuksi and Yawhee series. Azwell, Bagmont and Saydab are 20 to 40 inches to lithic or paralithic contact. Chewack, Fears, Hallihan, Naxing, and Tiptop are very deep. Wuksi soils have loamy coarse sand and sand volcanic ash mantles. Yawhee soils have a buried 2Btb horizon.
GEOGRAPHIC SETTING: The Burpeak soils are on steep backslopes of mountains at elevations of 4,800 to 5,800 feet. Slopes are 65 to 90 percent. These soils formed in colluvium and volcanic ash with minor amounts of glacial till from volcanic rock. The climate is characterized by cool, dry summers and cold, wet winters. Average annual precipitation is 25 to 35 inches. The average January temperature ranges from 18 to 22 degrees F., and the average July temperature ranges from 52 to 58 degrees F. The average annual temperature is 37 to 42 degrees F. The frost-free season is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buttoncreek and Ortellcreek soils. Buttoncreek soils are on fans and footslopes and have a 7 to 14 inch ash mantle. Ortellcreek soils have a 7 to 14 inch ash mantle over till on backslopes and footslopes.
DRAINAGE AND PERMEABILITY: Well drained, very rapid runoff, moderately rapid permeability.
USE AND VEGETATION: Used for wildlife habitat, recreation and watershed. Native vegetation is subalpine fir, Engelmann spruce, Douglas-fir, lodgepole pine with an understory of pachystima, myrtle blueberry, shinyleaf spiraea, western princes pine, pinegrass, red rocky mountain maple.
DISTRIBUTION AND EXTENT: Northcentral 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 - 0 to 4 inches (A horizon)
Cambic horizon - 6 to 34 inches (Bw1, Bw2, Bw3 horizons)
PSCS - zone from 2 to 42 inches (A, Bw1, Bw2, Bw3 and part of 2BC horizons) the upper part from 2 to 34 inches is ashy-skeletal and the lower part from 32 to 40 inches is loamy-skeletal.
Lithic contact - 47 inches (R horizon)