LOCATION STETATTLE WA

Established Series
Rev. CAB/SBC
08/2011

STETATTLE SERIES

The Stetattle series consists of very deep, well drained soils formed in volcanic ash mixed with colluvium and reworked glacial drift on debris aprons, valley walls, and debris cones. Slopes are 15 to 40 percent on debris cones and debris aprons and 40 to 90 percent on valley walls. The mean annual precipitation is about 1,800 millimeters. The mean annual temperature is about 3 degrees C.

TAXONOMIC CLASS: Medial-skeletal, amorphic Pachic Fulvicryands

TYPICAL PEDON: Stetattle very stony medial fine sandy loam, on a valley wall landform with a SW facing slope of 44 percent at 1890 meters elevation under herbaceous meadow vegetation. When described on September 17, 2007 the soil was dry throughout. (Colors are for moist soil unless otherwise noted.)

A1--0 to 12 cm; black (10YR 2/1) very stony medial fine sandy loam, very dark brown (10YR 2/2) dry; weak medium granular structure; soft, very friable, nonsticky, nonplastic; many very fine, fine, medium, and coarse roots; 5 percent fine gravel, 5 percent medium and coarse gravel, 10 percent cobbles, and 20 percent stones; extremely acid (pH 4.4); clear wavy boundary.

A2--12 to 30 cm; black (10YR 2/1) extremely stony medial fine sandy loam, dark brown (10YR 3/3) dry; moderate fine subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common very fine and fine roots, many medium roots, and few coarse roots; 10 percent fine gravel, 20 percent medium and coarse gravel, 10 percent cobbles, and 20 percent stones; very strongly acid (pH 4.8); clear wavy boundary.

A3--30 to 55 cm; black (10YR 2/1) extremely stony medial sandy loam, dark brown (10YR 3/3) dry; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common very fine and fine roots and few medium roots; 10 percent fine gravel, 25 percent medium and coarse gravel, 15 percent cobbles, and 35 percent stones; very strongly acid (pH 4.6); clear wavy boundary.

Bw--55 to 100 cm; very dark brown (10YR 2/2) extremely stony medial sandy loam, dark yellowish brown (10YR 4/4) dry; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; few very fine, fine, and medium roots; 10 percent fine gravel, 20 percent medium and coarse gravel, 15 percent cobbles, and 40 percent stones; very strongly acid (pH 4.7); clear wavy boundary.

2C--100 to 150 cm; dark olive brown (2.5Y 3/3) fragmental material with sand in interstices between rock fragments, olive brown (2.5Y 4/3) dry; single grain; 15 percent fine gravel, 25 percent medium and coarse gravel, 30 percent cobbles, and 20 percent stones.

TYPE LOCATION: North Cascades National Park, Chelan County, Washington; Section 30, T34N, R18E Willamette Meridian; McAlester Mountain, Washington USGS quadrangle; 48 degrees, 25 minutes, 16 seconds north latitude and 120 degrees, 39 minutes, 21 seconds west longitude; NAD83; UTM 673424 meters E, 5365772 meters N, zone 10.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 4 to 7 degrees C. Cryic soil temperature regime.
Soil moisture control section: dry for less than 30 consecutive days from June to October. Udic soil moisture regime.
Thickness of material with andic soil properties: 90 to 120 centimeters

A horizons:
Hue - 7.5YR or 10YR
Value - 2 to 3 moist, 3 to 4 dry
Chroma - 1 to 3 moist or dry
Fine earth texture - medial L, medial FSL or medial SL
Rock fragments - 10 to 85 percent total
10 to 35 percent gravel
5 to 25 percent cobbles
5 to 50 percent stones
Clay content - 3 to 10 percent
Volcanic glass - 30 to 60 percent
Reaction - extremely acid to strongly acid
Thickness - 50 to 120 centimeters

Bw horizons:
Hue - 7.5YR or 10YR
Value - 2 to 4 moist, 4 to 5 dry
Chroma - 2 to 6 moist or dry
Fine earth texture - medial FSL, medial SL or LS
Rock fragments - 40 to 85 percent total
10 to 35 percent gravel
10 to 40 percent cobbles
5 to 50 percent stones
Clay content - 1 to 8 percent
Volcanic glass - 5 to 50 percent
Reaction - very strongly acid to moderately acid
Thickness - 0 to 70 centimeters

2C horizon:
Hue - 2.5Y or 10YR
Value - 3 to 5 moist, 4 to 6 moist
Chroma - 3 or 4 moist or dry
Fine earth texture -LS, LCOS, or S
Rock fragments - 50 to 90 percent total
20 to 40 percent gravel
15 to 40 percent cobbles
10 to 30 percent stones
Clay content - 0 to 4 percent
Volcanic glass - 0 to 10 percent
Reaction - strongly acid to slightly acid

COMPETING SERIES: There are no competing series in this family. The Merriman and Quitter series have ferrihydritic mineralogy and are moderately deep to bedrock.

GEOGRAPHIC SETTING: The Stetattle soils are on debris aprons, valley walls, and debris cones at elevations of 1,100 to 1,981 meters. Slopes are 20 to 90 percent. These soils formed in volcanic ash mixed with reworked glacial drift and colluvium. The climate consists of cool, dry summers and cold, wet winters. Mean annual precipitation ranges from 1,800 to 3,300 millimeters, and mean annual air temperature ranges from 2 to 5 degrees C. Frost-free season is 30 to 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arriva (T), Doubtful (T), and Triumph (T) series. Arriva soils lack a pachic epipedon and form on stable depressions on passes. Doubtful soils lack melanic soil colors or organic carbon percentages that meet melanic requirements and form on the same landforms under coniferous vegetation. Triumph soils lack andic soil properties and form on the more active portions of the same landforms or on areas controlled by water erosion on the same landforms.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained soils, high to very high saturated hydraulic conductivity.

USE AND VEGETATION: Used for watershed, recreation, woodland and wildlife habitat. Native vegetation consists of Sitka alder, red elderberry, salmonberry, mountain ash, heather, lupine, sedges, starry false Solomon's seal, black huckleberry, fireweed, pearly everlasting, false hellebore, Indian paintbrush, and Sitka valerian.

DISTRIBUTION AND EXTENT: Western slopes of the North Cascade Mountains, Washington. MLRA 3. Series is of small extent.

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

SERIES ESTABLISHED: North Cascades National Park Service Complex, Washington; 2011.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: 0 to 100 centimeters
Andic soil properties: 0 to 100 centimeters (A1, A2, A3, and Bw horizons)
Lithologic discontinuity: 100 centimeters
Umbric epipedon: 0 to 100 centimeters (A1, A2, A3, and Bw horizons)

ADDITIONAL DATA: Laboratory data is available for this series. National Soil Survey Laboratory Pedon number 06N0798 (User Pedon ID 05WA057001).

National Cooperative Soil Survey
U.S.A.