LOCATION LEFTCREEK WAEstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy, mesic Lithic Vitrixerands
TYPICAL PEDON: Leftcreek-ashy-rangeland, on a south-facing 37 percent slope at an elevation of 1,850 feet. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
A--0 to 5 inches; light brownish gray (10YR 6/2) cobbly ashy sandy loam, dark grayish brown (10YR 4/2) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium roots; common very fine and fine irregular pores; 15 percent pebbles, 10 percent cobbles, and 5 percent stones; slightly acid (pH 6.4); gradual wavy boundary. (2 to 8 inches thick)
Bw--5 to 14 inches; pale brown (10YR 6/3) very cobbly ashy sandy loam, dark grayish brown (10YR 4/2) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium roots; common very fine and fine irregular pores; 20 percent pebbles, 15 percent cobbles, and 5 percent stones; slightly acid (pH 6.4); abrupt wavy boundary. (8 to 18 inches thick)
2R--14 inches; granite.
TYPE LOCATION: Okanogan County, Washington, about 4 miles south of Methow, Washington; 1,200 feet south and 500 feet east of the northwest corner of section 36, T. 30 N., R. 22 E. (Latitude 48 degrees 03 minutes 35 seconds N., Longitude 120 degrees 02 minutes 00 seconds W.)
RANGE IN CHARACTERISTICS: The average annual soil temperature is 47 to 52 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 75 to 90 consecutive days following the summer solstice. Depth to bedrock is 10 to 20 inches. The solum has an estimated moist bulk density of 0.60 to 0.85 g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.4 to 1.0 percent, 15-bar water retention of 5 to 12 percent for air dried samples and averages 35 to 70 percent rock fragments. Reaction is slightly acid to neutral throughout.
The A horizon has value of 4 through 6 dry, 2 through 4 moist, and chroma of 1 through 3 dry or moist.
The Bw horizon has value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 or 3 dry or moist. It is ashy sandy loam or ashy coarse sandy loam, and it is very gravelly or very cobbly. It has 20 to 50 percent pebbles, 0 to 20 percent cobbles, and 0 to 5 percent stones.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Leftcreek soils are found on upper backslopes, shoulders, and ridges of mountains, usually on slopes with southerly aspects. Elevation ranges from 1,400 to 4,800 feet. Slopes are 35 to 65 percent. They form in volcanic ash mixed with residuum and colluvium. The climate is characterized by warm, dry summers and cool, moist winters. Average annual precipitation is 12 to 18 inches. The average January temperature ranges from 25 to 30 degrees F, the average July temperature ranges from 65 to 70 degrees F, and average annual temperature ranges from 47 to 52 degrees F. The frost-free season ranges from 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goldcreek, Kedar, Vinegar, and Vingulch soils. Goldcreek and Vinegar soils are forested, greater than 60 inches deep, and found on backslopes and footslopes in frigid temperature regimes. Kedar soils are forested , greater than 60 inches deep, and found on backslopes and footslopes. Vingulch soils are forested, have bedrock at 20 to 40 inches, and found on shoulders and upper backslopes in frigid temperature regimes.
DRAINAGE AND PERMEABILITY: Well drained, rapid; moderately rapid permeability.
USE AND VEGETATION: Used for livestock grazing, wildlife habitat, watershed, and recreation. Native vegetation is bluebunch wheatgrass, antelope bitterbrush, arrowleaf balsamroot, Idaho fescue, and common yarrow.
DISTRIBUTION AND EXTENT: Northcentral Washington; MLRA 6. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Okanogan National Forest, Okanogan County, Washinton, 2005.
REMARKS: Diagnostic properties and features recognized in this pedon include:
Ochric epipedon
Cambic horizon - 5 to 14 inches (Bw horizon)
PSCS - zone from 0 to 14 inches (A and Bw horizons)
Lithic Contact - 14 inches