LOCATION SNIDERPEAK WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic Typic Haplocryands
TYPICAL PEDON: Sniderpeak extremely gravelly medial sandy loam-forestland, on a 70 percent northwesterly aspect at an elevation of 2,500 feet in a Pacific silver fir/salal-deerfern plant association. (When described on January 19, 1994, the soil was moist throughout. Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 3 inches; slightly decomposed needles, leaves, twigs, and log fragments; abrupt smooth boundary. (1 to 5 inches thick)
Oe--3 to 4 inches; moderately decomposed organic materials; abrupt smooth boundary. (0.5 to 1.5 inches thick)
A--4 to 9 inches; dark yellowish brown (10YR 3/4) extremely gravelly medial sandy loam, yellowish brown (10YR 5/6) dry; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, nonsticky and nonplastic; moderately smeary; common very fine, fine, medium, and coarse roots; common very fine and fine irregular pores; 55 percent gravel, 15 percent cobbles; strongly acid (pH 5.4); clear smooth boundary. (4 to 9 inches thick)
Bw1--9 to 24 inches; dark yellowish brown (10YR 3/6) extremely gravelly medial sandy loam, brownish yellow (10YR 6/6) dry; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, nonsticky and nonplastic; moderately smeary; common very fine, fine, medium, and coarse roots; common very fine and fine irregular pores; 45 percent gravel, 25 percent cobbles; moderately acid (pH 5.8); clear wavy boundary.
Bw2--24 to 32 inches; dark yellowish brown (10YR 3/6) extremely cobbly medial sandy loam, yellow (10YR 7/6) dry; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, nonsticky and nonplastic; moderately smeary; common very fine, fine, medium, and coarse roots; common very fine and fine irregular pores; 30 percent gravel, 35 percent cobbles; moderately acid (pH 6.0); clear wavy boundary. (Combined thickness of the Bw horizon is 16 to 31 inches thick.)
R--32 inches; fractured hard volcanic rock.
TYPE LOCATION: Clallam County, Washington, about 2 miles northwest of Littleton Loop trail head, about 1,450 feet east and 2,800 feet north of the southwest corner of Section 18, T. 30 N., R. 10 W. (Latitude 48 degrees, 05 minutes, 41 seconds N., Longitude 124 degrees, 02 minutes, 32 seconds W.)
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 41 to 43 degrees F. The mean summer soil temperature is 43 to 47 degrees F. The mean annual winter soil temperature is 37 to 41 degrees F. The difference between the mean summer and mean winter soil temperature is 6 to 9 degrees F. These soils are usually moist, and are dry 0 to 30 consecutive days in the soil moisture control section; udic moisture regime. Depth to bedrock is 20 to 40 inches. The particle-size control section from the mineral soil surface to the bedrock contact has andic soil properties and 60 to 90 percent rock fragments by volume. The andic soil material has an estimated moist bulk density of 0.70 to 0.90 g/cc, acid-oxalate extractable aluminum plus one half of the acid-oxalate extractable iron of 2 to 3 percent, phosphate retention of 85 to 100 percent, and 15-bar water retention of 15 to 30 percent for air dried samples. It has 1 to 2 cmol/kg of aluminum. Acid oxalate extractable iron is 1.5 to 3.0 percent. It has 8 to 18 percent field estimated clay.
The A horizon has hue of 10YR or 7.5YR moist and dry and chroma of 3 or 4 moist and 3, 4, or 6 dry. Reaction is strongly or moderately acid. It has 5 to 15 percent organic matter.
The Bw horizon has hue of 10YR or 7.5Y moist and dry, value of 5 through 7 dry, and chroma of 3, 4, or 6 moist and 4 or 6 dry. It is extremely gravelly medial sandy loam, extremely gravelly medial loam, or extremely cobbly medial sandy loam. The horizon is weakly or moderately smeary. Reaction is moderately acid. It has 1 to 7 percent organic matter.
COMPETING SERIES: These are the Balcher, Blackjack, Fahnestock, Kahkwa, Mueller, Musgrove, Sorethumb, Stonybrook, and Tylerpeak series. Balcher soils are moderately well drained. Blackjack, Fahnestock, and Kahkwa soils are deep. Mueller, and Musgrove soils are very deep. Sorethumb soils formed in colluvium and residuum from sedimentary and metasedimentary rocks. Sorethumb soils have a difference between mean summer and mean winter soil temperature of 3 to 5 degrees F. Stonybrook soils are strongly acid throughout the subsoil. Tylerpeak soils have hard bedrock at 20 to 40 inches.
GEOGRAPHIC SETTING: Sniderpeak soils are predominantly on continental glaciated mountain slopes. Slopes are 15 to 90 percent. The soils formed in colluvium and residuum from marine basalt and associated volcanic rocks. Elevations are 2,500 to 4,000 feet. Average annual precipitation is 50 to 105 inches. Average annual temperature is 39 to 43 degrees F. The frost-free season is 120 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Balcher and Fahnestock soils and Buckman and Urgestein soils. Buckman soils are very shallow. Urgestein soils have an umbric epipedon.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is Pacific silver fir, western hemlock, Douglas-fir, deerfoot vanillaleaf, oneleaf foamflower, salal, deer fern, Alaska huckleberry, western swordfern, red huckleberry, queencup beadlily, devil's club, threeleaf foamflower, and northern twinflower.
DISTRIBUTION AND EXTENT: Northern slope of Olympic Mountains, Clallam County, 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 the following:
Ochric epipedon
Cambic horizon - 9 to 32 inches
Andic soil properties - 4 to 32 inches
Lithic contact - 32 inches
PSCS - 4 to 32 inches
All depths to diagnostic horizons or other features are measured from the top of the first mineral horizon.