LOCATION MILLERPOINT WAEstablished Series
TAXONOMIC CLASS: Ashy, mixed Typic Vitricryands
TYPICAL PEDON: Millerpoint ashy sandy loam - forestland, on a 12 percent east-facing slope at an elevation of 5,840 feet. (colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Oi--0 to 1 inch; slightly decomposed forest litter; abrupt smooth boundary. (0.5 to 2 inches thick)
C--1 to 3 inches; gray (10YR 5/1) ashy loamy sand, light gray (10YR 7/1) dry; single grain; loose, very friable, nonsticky and nonplastic; many very fine and fine and few medium and coarse roots; many very fine and fine and few medium coarse irregular pores; 50 percent pumice less than 2mm in size; NaF pH 9.2; slightly acid (pH 6.4); abrupt smooth boundary. (0 to 2 inches thick)
A1--3 to 5 inches; brown (10YR 4/3) ashy sandy loam, pale brown (10YR 6/3) dry; weak fine and medium granular structure; loose, very friable, nonsticky and nonplastic; weakly smeary; many very fine and fine and few medium and coarse roots; many very fine and fine irregular pores; 20 percent pumice less than 2 mm in size; NaF pH 11.2; slightly acid (pH 6.4); clear smooth boundary.
A2--5 to 14 inches; brown (10YR 4/3) ashy sandy loam, pale brown (10YR 6/3) dry; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; weakly smeary; many very fine and fine and few medium and coarse roots; many very fine and fine irregular pores; 10 percent pumice less than 2 mm in size; 5 percent gravel; NaF pH 11.2; slightly acid (pH 6.4); gradual smooth boundary. (Combined thickness of A horizon is 8 to 14 inches.)
Bw1--14 to 24 inches; dark yellowish brown (10YR 3/6) gravelly ashy fine sandy loam, light yellowish brown (10YR 6/4) dry; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; weakly smeary; common fine and few medium and coarse roots; many very fine and fine irregular pores; 10 percent gravel and 5 percent cobbles; NaF 10.6; slightly acid (pH 6.2); gradual smooth boundary.
Bw2--24 to 42 inches; yellowish brown (10YR 5/6) gravelly ashy fine sandy loam, very pale brown (10YR 7/4); moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; weakly smeary; few very fine and fine roots; many very fine and fine irregular pores; 10 percent gravel and 5 percent cobbles; NaF pH 10.6; moderately acid (pH 6.0); gradual smooth boundary. (Combined thickness of the 2Bw horizon is 28 to 48 inches.)
2Bw3--42 to 63 inches; yellowish brown (10YR 5/6) fine sandy loam, very pale brown (10YR 7/4) dry; moderate coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; weakly smeary; few very fine and fine irregular pores; 5 percent gravel; NaF 9.6; moderately acid (pH 6.0); gradual smooth boundary. (Combined thickness of 3Bw horizon is 10 to 20 inches.)
TYPE LOCATION: Yakima County, Washington; about 8 miles southeast of White Pass; about 1,500 feet east and 1,800 feet south of the northwest corner of section 3, T. 12, N., R. 12, E.; Latitude 46 degrees, 33 minutes, 46 seconds N. and Longitude 121 degrees, 18 minutes, 10 seconds W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature at 20 inches is 39 to 44 degrees F. Estimated mean summer soil temperature is 42 to 45 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 25 to 45 consecutive days following the summer solstice (udic moisture regime). The thickness of andic soil material is 36 to more than 40 inches and it has estimated moist bulk density of 0.65 to 0.85 g/cc, glass content of 5 to 30 percent, acid-oxalate extractable aluminum plus one-half the acid-oxalate extractable iron of 2 to 5 percent, phosphate retention is 50 to 65 percent and 15 bar water retention for air dried samples is 8 to 12 percent. The lower part of the particle size control section contains 15 to 35 percent rock fragments.
The A horizon has hue of 7.5YR or 10YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 through 6 moist or dry.
The Bw horizon has value of 3 through 5 moist, 5 through 7 dry and chroma of 3 through 6 moist or dry. Texture is ashy sandy loam, gravelly ashy sandy loam or gravelly ashy fine sandy loam. Rock fragments average 0 to 30 percent. Reaction is slightly acid or moderately acid.
The 2Bw horizon has hue of 7.5YR or 10YR, value of 3 through 5 moist, 5 through 7 dry and chroma of 4 through 6 moist or dry. Texture is fine sandy loam or gravelly fine sandy loam with 2 to 35 percent rock fragments.
Some pedons have a 2C horizon with 20 to 35 percent rock fragments.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Millerpoint soils are on plateaus, ridges and mountain side slopes. Slopes are 0 to 60 percent. These soils formed in volcanic ash over colluvium from andesite, mudflow deposits, or block and ash flow deposits. Elevations are 3,900 to 6,500 feet. Climate is characterized by warm, dry summers and cold, wet winters. The mean annual precipitation is 50 to 80 inches. The average January temperature is about 22 degrees F. and the average July temperature is about 60 degrees F. The mean annual temperature is 37 to 43 degrees F. The frost-free season is 35 to 75 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Littlebald and Nomlas soils. Littlebald soils are found on plateaus, ridges and mountain side slopes and have an umbric epipedon. Nomlas soils are on mountain side slopes and are ashy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for timber production, recreation and wildlife habitat. Native vegetation is mountain hemlock, Pacific silver fir, subalpine fir, Engelmann spruce, Alaska yellow cedar and whitebark pine with an understory of beargrass, big huckleberry, Cascade azalea, sidebells pyrola and grouse huckleberry.
DISTRIBUTION AND EXTENT: Yakima County, WA. MLRA 3 and 6. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wenatchee National Forest, Naches Ranger District, Yakima County, Washington, 2003.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 1 to 14 inches (A1 and A2 horizons)
Andic soil properties - 1 to 42 inches (C, A1, A2, Bw1, and Bw2 horizons)
Cambic horizon - 14 to 63 inches (Bw1, Bw2 and 2Bw3 horizons)
Particle-size control section - zone from 1 to 41 inches (C, A1, A2, Bw1 and part of 2Bw2 horizons)
Cryic soil temperature regime
Udic soil moisture regime
The thickness range of the zone meeting andic soil properties was revised from 25 to 40 inches or more to 36 to 40 inches or more. Based on the definition of contrasting particle-size class, a contrasting layer 5 inches thick within the 40 inch particle-size control section, is the minimum requirement needed. Those Millerpoint soils with an ash mantle less than 36 inches meeting andic soil properties, will be considered a taxadjunct to the series.
Mineralogy is based on lab data from the associated Littlebald series.