LOCATION MAIDENPEAK         WA
Established Series
Rev. RGC/HJP/DAL/TDT
06/2000

MAIDENPEAK SERIES


The Maidenpeak series consists of deep and very deep, well drained soils that formed in colluvium from marine basalt and associated volcanic rocks on mountain slopes. Slopes are 60 to 90 percent. The average annual precipitation is about 50 inches and average annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Medial-skeletal, ferrihydritic, frigid Typic Hapludands

TYPICAL PEDON: Maidenpeak extremely gravelly medial sandy loam forestland, on a 76 percent slope with a northerly aspect at an elevation of 2,025 feet in a Western hemlock/Pacific rhododendron-western swordfern plant association. (When described on June 29, 1993, the soil was moist throughout. Colors are moist soil unless otherwise stated. All textures are apparent field textures.)

Oi--0 to 2 inches; slightly decomposed needles, leaves, twigs, and cone fragments; abrupt wavy boundary. (1 to 3 inches thick)

A--2 to 8 inches; dark brown (10YR 3/3) extremely gravelly medial sandy loam, yellowish brown (10YR 5/4) dry; weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine and fine and common medium and coarse roots; common very fine and fine irregular pores; 60 percent gravel, 10 percent cobbles; moderately acid (pH 5.6); clear wavy boundary. (3 to 7 inches thick)

Bw1--8 to 13 inches; dark yellowish brown (10YR 3/4) extremely gravelly medial sandy loam, yellowish brown (10YR 5/4) dry; weak very fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine and fine irregular pores; 55 percent gravel, 15 percent cobbles; moderately acid (pH 5.8); clear wavy boundary.

Bw2--13 to 19 inches; dark yellowish brown (10YR 3/6) 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, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine irregular pores; 50 percent gravel, 20 percent cobbles; moderately acid (pH 6.0); clear wavy boundary.

Bw3--19 to 40 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, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine irregular pores; 50 percent gravel, 25 percent cobbles; moderately acid (pH 6.0); clear wavy boundary. (Combined thickness of the Bw horizon is 30 to 45 inches.)

BC--40 to 62 inches; dark yellowish brown (10YR 3/6) extremely gravelly 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, slightly sticky and slightly plastic; few very fine, fine, and medium roots; few very fine irregular pores; 50 percent gravel, 25 percent cobbles; slightly acid (pH 6.2).

TYPE LOCATION: Clallam County, Washington, about 2 miles west of Big Skidder Hill, about 100 feet west and 1,950 feet north of the southeast corner of section 31, T. 29 N., R. 2 W. (Latitude 47 degrees, 57 minutes, 34 seconds N., Longitude 122 degrees, 58 minutes, 23 seconds W.)

RANGE IN CHARACTERISTICS: Mean annual soil is temperature is 44 to 47 degrees F. These soils are usually moist, and are dry in the soil moisture control section 30 to 45 consecutive days following the summer solstice; udic moisture regime. Depth to bedrock is 40 to over 60 inches. The particle-size control section has andic soil properties with 60 to 90 percent rock fragments by volume. The andic soil material has an estimated moist bulk density of 0.60 to 0.90 g/cc, an 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 25 percent for air dried samples. It has 1 to 2 cmol/kg of aluminum. Acid oxalate extractable iron is 1.5 to 2.5 percent.

The A horizon has hue of 10YR or 7.5YR moist and chroma of 3 or 4 moist and dry. It has 5 to 10 percent organic matter.

The Bw horizon has hue of 10YR or 7.5YR moist, value of 5 through 7 dry, and chroma of 4 or 6 moist and dry. It is extremely gravelly medial sandy loam, extremely gravelly medial loam, or extremely cobbly medial sandy loam. Reaction is moderately or slightly acid. It has 1 to 7 percent organic matter.

The BC horizon has an estimated moist bulk density of 0.90 to 1.20 g/cc. It has less than 1 to 2 percent organic matter.

COMPETING SERIES: These are the Duckabush, Fricaba, Gunderson, Lotloh, Ruggedridge and Halfoss series. Fricaba, Ruggedridge and Halfoss soils are moderately deep to bedrock. Gunderson soils are deep to dense glacial till. Duckabush soils are dry for 0 to 20 consecutive days. Lotloh soils are derived from sedimentary bedrock and have 40 to 60 percent sand in the particle-size control section.

GEOGRAPHIC SETTING: Maidenpeak soils are on mid-slopes of mountains. Slopes are 60 to 90 percent. The soils formed in colluvium from volcanics and metavolcanics. Elevations are 1,900 to 2,900 feet. Average annual precipitation is 35 to 70 inches. Average annual temperature is 42 to 45 degrees F. The frost-free season is 150 to 170 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Graywolf, Halfoss, Juandefuca, Pennycreek, Slidecamp, Station, and Tunnelcreek soils. Graywolf soils are on low relief dissected uplands and have an argillic horizon. Halfoss and Tunnelcreek soils are on mountain slopes and are 20 to 40 inches to bedrock. Juandefuca, Pennycreek and Tunnelcreek soils are on mountain slopes and have a xeric moisture regime. Pennycreek soils are on mountain slopes and are 4 to 10 inches to bedrock. Station soils are on mountain slopes and are 10 to 20 inches to bedrock. Slidecamp soils are on low relief dissected uplands and have an argillic horizon with less than 35 percent rock fragments.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is Douglas-fir, western hemlock, western redcedar, Pacific rhododendron, western swordfern, salal, and red huckleberry.

DISTRIBUTION AND EXTENT: Clallam and Jefferson Counties, Washington; MLRA 1. 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 - 8 to 40 inches
Andic soil properties - 2 to 40 inches
PSCS - 2 to 42 inches; from 2 to 40 inches is medial-skeletal and ferrihydritic and from 40 to 42 inches is loamy-skeletal and isotic; the thickest part is medial-skeletal.

All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.


National Cooperative Soil Survey
U.S.A.