LOCATION SNOWCREEK          WA
Established Series
Rev. RGC/HJP/DAL/TDT
08/2006

SNOWCREEK SERIES


The Snowcreek series consists of moderately deep to bedrock, well drained soils that formed in colluvium from marine basalt and associated volcanics on mountain slopes. Slopes are 60 to 90 percent. Average annual precipitation is about 55 inches and average annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, isotic Haploxerandic Dystrocryepts

TYPICAL PEDON: Snowcreek extremely gravelly medial sandy loam - forestland, on a 65 percent west-facing slope at an elevation of 3,720 feet in a western hemlock/Pacific rhododendron-salal plant association. (When described on May 14, 1992, the soil was moist throughout. Colors are for dry soil unless otherwise stated.)

Oi--0 to 1 inch; slightly decomposed needles, leaves, and twigs; abrupt wavy boundary. (0.5 to 2 inches thick)

A--1 to 4 inches; yellowish brown (10YR 5/4) extremely gravelly medial sandy loam, dark brown (10YR 3/3) moist; weak very fine and fine granular and weak very fine and fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; weakly smeary; many very fine and fine and common medium and coarse roots; common very fine and fine irregular pores; 45 percent gravel, 20 percent cobbles; moderately acid (pH 5.8); abrupt wavy boundary. (3 to 8 inches thick)

Bw1--4 to 9 inches; yellowish brown (10YR 5/4) extremely gravelly medial sandy loam, dark yellowish brown (10YR 3/4) moist; weak very fine and fine granular and weak very fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine and fine irregular pores; 65 percent gravel, 20 percent cobbles; moderately acid (pH 5.6); clear wavy boundary.

Bw2--9 to 23 inches; yellowish brown (10YR 5/6) extremely cobbly sandy loam, dark yellowish brown (10YR 3/6) moist; weak very fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, fine, medium, and coarse roots; common very fine irregular pores; 35 percent gravel, 40 percent cobbles; moderately acid (pH 5.6); abrupt wavy boundary. (Combined thickness of the Bw horizon is 18 to 32 inches.)

R--23 inches; hard metavolcanic rock.

TYPE LOCATION: Clallam County, Washington, about 1.5 miles southwest of Mt. Zion, about 165 feet east and 2,110 feet south of the northwest corner of section 27, T. 28 N., R. 3 W. (Latitude 47 degrees, 54 minutes, 18 seconds N., Longitude 123 degrees, 1 minutes, 55 seconds W.)

RANGE IN CHARACTERISTICS: Mean annual soil temperature is 43 to 45 degrees F. The mean summer soil temperature is 45 to 47 degrees F. The mean winter soil temperature is 37 to 41 degrees F. These soils are usually moist but are dry in all parts of the soil moisture control section for 45 to 60 consecutive days following the summer solstice. Depth to bedrock is 20 to 40 inches. The upper 7 to 12 inches of the solum has a moist bulk density of 0.85 to 1.00 g/cc and an acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 1 to 2 percent. The particle-size control section has 60 to 90 percent rock fragments by volume and 8 to 18 percent clay.

The A horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, and chroma of 2 through 4 dry and 1 through 3 moist.

The Bw horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry, and chroma of 4 or 6 dry and moist. It is extremely gravelly sandy loam or extremely cobbly sandy loam. Reaction is moderately or slightly acid.

COMPETING SERIES: These are the Alfir, Deserter, Puzzlecreek, Skinwood and Terence series Alfir, Deserter and Terence soils are over 60 inches deep. Puzzlecreek soils have an umbric epipedon 10 to 25 inches thick. Skinwood soils have extremely acid or very strongly acid pH in the cambic horizon, and have an udic soil moisture regime.

GEOGRAPHIC SETTING: Snowcreek soils are on south-facing slopes of mountains. Slopes are 60 to 90 percent. The soils formed in colluvium from marine basalt and associated volcanics. Elevations are 3,100 to 4,400 feet. Average annual precipitation is 40 to 70 inches. Average annual temperature is 42 to 44 degrees F. and frost-free season is 140 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bungalow, Deserter, Mueller, Shanty, and Tylerpeak soils. Bungalow soils are on mountain slopes and are 4 to 10 inches to bedrock. Deserter and Mueller soils are on mountain slopes and are very deep. Shanty soils are on mountain slopes and are 10 to 20 inches to bedrock. Tylerpeak soils are on mountain slopes and have a udic moisture regime. Bungalow, Mueller and Tylerpeak soils are on adjacent north slopes and have andic soil properties to a depth of 14 inches or more.

DRAINAGE AND PERMEABILITY: Well drained; rapid and very rapid runoff; moderately rapid permeability.

USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is Douglas-fir, western hemlock, subalpine fir, western white pine, lodgepole pine, Pacific rhododendron, salal, Oregon-grape, and kinnikinnick.

DISTRIBUTION AND EXTENT: Clallam and Jefferson Counties, Washington; MLRA 3. Series is of small extent.

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

SERIES ESTABLISHED: Clallam County, Washington, 2000; Olympic National Forest.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon
Cambic horizon - 4 to 23 inches (Bw1 and Bw2 horizons)
Andic subgroup properties - 1 to 9 inches (A and Bw1 horizons)
Lithic contact - at 23 inches
Particle-size control section - 11 to 23 inches (Bw2 horizon)
Xeric soil moisture regime


National Cooperative Soil Survey
U.S.A.