LOCATION COTTERAL WAEstablished Series
TAXONOMIC CLASS: Pumiceous or ashy-pumiceous over medial, glassy over amorphic Andic Haplocryods
TYPICAL PEDON: Cotteral very paragravelly sandy loam - forested. (Colors are for moist soil unless otherwise stated. When described pedon was dry to 32 inches and moist below.)
Oe--2 to 1 inch; partially decomposed needles, twigs, leaves, bark.
Oa--1 inch to 0; decomposed organic material.
E--0 to 3 inches; dark gray (10YR 4/1) very paragravelly sandy loam, light brownish gray (10YR 6/2) dry; weak medium and coarse granular structure; soft, very friable, nonsticky, nonplastic and weakly smeary; many fine, medium, and coarse roots; about 60 percent by volume of 2-10 mm gravel-size pumice; slightly acid (pH 5.7); abrupt wavy boundary. (.5 to 4 inches thick)
Bs1--3 to 6 inches; mottled dark reddish brown (5YR 3/4) reddish brown (5YR 4/3) and grayish brown (10YR 5/2) very paragravelly sandy loam, strong brown (7.5YR 5/8) brown (7.5YR 5/4), and light gray (10YR 7/1) dry; weak medium and coarse granular structure; soft, very friable, nonsticky, nonplastic and weakly smeary; many fine, medium, and coarse roots; about 60 percent by volume of 2-10 mm gravel-size pumice; slightly acid (pH 5.8); abrupt wavy boundary. (2 to 5 inches thick)
Bs2--6 to 30 inches; white (10YR 8/1) and yellowish red (5YR 5/8) extremely paragravelly, white (10YR 8/1) and strong brown (7.5YR 5/8) dry; single grain; loose; many fine, medium, and coarse roots; about 70 percent by volume of 2-10 mm gravel-size pumice; slightly acid (pH 5.8); abrupt wavy boundary. (10 to 33 inches thick)
2Bsb--30 to 60 inches; dark yellowish brown (10YR 4/4) silt loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; slightly hard, very friable, nonsticky, nonplastic and weakly smeary; common fine, medium, and coarse roots; about 2 percent unweathered pebbles and 5 percent cobbles; moderately acid (pH 5.8).
TYPE LOCATION: Lewis County, Washington; St. Regis Tree Farm; 10 miles northeast of Morton; 450 feet west of the end of road No. 1045, 1,900 feet north, 75 feet west of southeast corner of sec. 4, T. 13 N., R. 6 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 42 degrees to 44 degrees F. and the mean annual soil temperature where there is an 0 horizon is about 45 degrees F. The upper part of the 10- to 40-inch control section contains 50 to 90 percent volcanic pumice that ranges from 2 to 50 mm in size. The lower part of the control section is silt loam to sandy loam texture. The thickness of the cindery mantle over the medial buried horizon ranges from 18 to 37 inches. These soils are usually moist.
The E horizon has hue of 7.5YR or 10YR, value of 2 through 6 moist, 5 through 7 dry, and chroma of 1 or 2 moist or dry. Reaction is very strongly acid to neutral.
The Bs horizons have value of 3 through 5 moist and 4 through 7 dry in the upper part. It is very cindery or extremely cindery, sandy loam, or sand in the upper part grading to cinders. Reaction is strongly acid to neutral.
The underlying 2Bs horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 3 through 5 moist and 4 through 6 dry. It is sandy loam, loam, or silt loam and contains 2 to 10 percent coarse fragments. Some pedons have a 2Ab or 2Eb horizon. Reaction is moderately acid to neutral.
COMPETING SERIES: There are no competing series. The Cattcreek, Kweo, Lapine, Maklak, and Wedge series in other families. Cattcreek soils are cindery over medial-skeletal. Kweo, Lapine and Maklak soils lack a spodic horizon. Wedge soils lack contrasting textures in the particle-size control section.
GEOGRAPHIC SETTING: These soils are on mountain slopes at elevations from 2,800 to 4,900 feet. Slopes range from 0 to 65 percent. The soil formed in a slightly weathered pumice mantle over sandy loam and/or silt loam high in volcanic ash. Average annual precipitation ranges from 90 to 110 inches. Mean January temperature is 28 degrees F, mean July temperature is 55 degrees F, and mean annual temperature is 41 degrees F. The growing season (28 degrees F.) is 100 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bellicum and Bromo soils and the competing Cattcreek soils. Bellicum soils are cindery over medial-skeletal, and are frigid. Bromo soils have frigid temperatures and have an umbric epipedon.
DRAINAGE AND PERMEABILITY: Well drained; medium to slow runoff; moderately rapid permeability in the E and Bs1 horizon, very rapid in the Bs2 horizon, and moderate in th 2Bsb horizon.
USE AND VEGETATION: Used for woodland, watershed, and wildlife habitat. Cover is Douglas-fir, Pacific silver fir, western hemlock, western redcedar, noble fir, Alaska cedar, and western white pine, with an understory of beargrass, red huckleberry, princes pine, western swordfern, western redcedar, noble fir, Alaska-cedar, and western white pine.
DISTRIBUTION AND EXTENT: Central Cascade Mountains near Mt. St. Helens. This soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, 1976.
REMARKS: Classification changed 6/98 because of recent amendments to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are an albic horizon from the mineral surface to 3 inches, a spodic horizon from 3 to 30 inches, and a particle-size control section from 10 to 40 inches that is cindery (70 percent cinders) from 10 to 30 inches, and dominated by amorphous material from 30 to 40 inches.
ADDITIONAL DATA: Partial laboratory data are available on this soil. Soil sample number is R74-36 - Lewis County.