LOCATION RUGLES WAEstablished Series
TAXONOMIC CLASS: Medial over loamy, amorphic over isotic, frigid Typic Hapludands
TYPICAL PEDON: Rugles silt loam-forested. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
0e--2 to 0 inches; duff layer composed of partially decomposed twigs and needles, abrupt smooth boundary. (2 to 5 inches thick)
A--0 to 4 inches; very dark grayish brown (10YR 3/2) silt loam, dark yellowish brown (10YR 4/4) dry; strong medium granular structure; slightly hard, friable, slightly sticky, slightly plastic, weakly smeary; many fine and very fine, and common coarse roots; strongly acid (pH 5.2); abrupt wavy boundary. (3 to 9 inches thick)
AB--4 to 11 inches; dark brown (10YR 4/3) silt loam, light yellowish brown (2.5Y 6/4) dry; moderate medium subangular blocky structure parting to moderate medium granular structure; hard, friable, slightly sticky, slightly plastic, weakly smeary; many fine and very fine roots; strongly acid (pH 5.2); abrupt wavy boundary. (6 to 10 inches thick)
Bw1--11 to 16 inches; dark brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; moderate coarse subangular blocky parting to moderate medium granular structure; hard, friable, slightly sticky, slightly plastic, moderately smeary; many fine and very fine roots; strongly acid (pH 5.4); clear wavy boundary. (6 to 12 inches thick)
Bw2--16 to 32 inches; grayish brown (10YR 5/2) silt loam, white (2.5Y 8 2) dry; moderate coarse subangular blocky structure; hard, friable, slightly sticky, plastic, weakly smeary; common fine and very fine roots; moderately acid (pH 5.6); gradual smooth boundary. (7 to 20 inches thick)
Bw3--32 to 45 inches; grayish brown (10YR 5/2) silt loam, white (2.5Y 8/2) dry; moderate coarse subangular blocky structure; hard, friable, slightly sticky, plastic, moderately smeary; common fine and very fine roots; moderately acid (pH 5.6); gradual smooth boundary. (5 to 20 inches thick)
BC--45 to 57 inches; grayish brown (10YR 5/2) silt loam, white (2.5Y 8 2) dry; moderate very coarse subangular blocky structure; hard, friable, slightly sticky, plastic; few thin clay films coating mineral grains; moderately acid (pH 5.6); abrupt smooth boundary. (9 to 12 inches thick)
C--57 to 60 inches, grayish brown (2.5Y 5/2) silty clay loam, white (2.5Y 8/2) dry; with common fine distinct mottles, strong brown (7.5YR 5/6) reddish yellow (7.5YR 7/6) dry; massive; slightly hard, firm, slightly sticky, plastic; stratified; common very fine discontinuous tubular pores; few thin clay films coating mineral grains; moderately acid (pH 5.8).
TYPE LOCATION: Snoqualmie Pass Area, Pierce County, Washington; 150 feet north of St. Regis Paper Company Road #0-501, about 1/4 miles east of intersection with road #0-500; SW1/4NW1/4 sec. 24, T. 17 N., R. 5 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 43 to 47 degrees F. The solum thickness ranges from 40 to 60 inches. Mottles occur at varying depths below 30 inches. The control section is silt loam or silty clay loam and contains 0 to 10 percent pebbles. Pedons range from weakly smeary to moderately smeary throughout the control section.
The A horizon has value of 2 to 6 moist or dry, and chroma of 2 to 4 moist or dry. Some pedons have soft iron-manganese segregations.
The AB horizon has value of 4 or 5 moist, 5 to 7 dry, and chroma of 2 to 4 moist or dry.
The Bw horizon has a value of 4 to 6 moist and chroma of 2 to 4 moist. Texture is silt loam or silty clay loam. Some pedons have patchy thin clay films in the lower B and C horizons. Reaction is strongly acid or moderately acid.
The C horizon has value of 5 or 6 moist, 6 to 8 dry, and chroma of 2 or 3 moist or dry. Clay content is 27 to 35 percent.
COMPETING SERIES: These are the Tolany and Zynbar soils. Tolany soils have hue of 5YR or 7.5YR and are 10 to 35 percent hard concretions in the particle-size control section. Zynbar soils are gravelly in the control section and have hue of 10YR throughout.
GEOGRAPHIC SETTING: Rugles soils are on dissected terraces. Slopes are 0 to 30 percent. Elevation ranges from 1,700 to 2,400 feet. Rugles soils formed in lacustrine deposits associated with valley glaciation high in tephra. The average annual precipitation ranges from 50 to 70 inches; mean January temperature is about 30 degrees F.; mean July temperature is about 59 degrees F.; and the mean annual air temperature is about 44 degrees F. The growing season (28 degrees F) is 150 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Jonas, Mashel, Wilkeson, and the competing Zynbar soils. Jonas soils have an umbric epipedon. Mashel soils have a fine textured argillic horizon. Wilkeson soils have a fine-loamy argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability.
USE AND VEGETATION: Used for timber production, watershed and wildlife habitat. Native vegetation is Douglas-fir, western hemlock, western redcedar, and red alder, with an understory of western swordfern, western brackenfern, deer fern, bedstraw, red huckleberry, huckleberry, trillium, and vine maple.
DISTRIBUTION AND EXTENT: Foothills on the west slopes of the Cascade Mountains in west-central Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snoqualmie Pass Area, Pierce County, Washington, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the mineral surface to 11 inches, and a cambic horizon from 11 to 57 inches. The upper part of the profile from the mineral surface to 16 inches is estimated to have a bulk density of 0.85 g/cc or less.