LOCATION SWAKANE WA
Established Series
Rev. VB/EMM/RWL
06/2016
SWAKANE SERIES
Landscape--hills, mountains
Landform--mountain slopes, hillslopes, foothills
Slope--0 to 90 percent
Parent material--residuum and colluvium derived from granite, granodiorite, quartz monzonite, and granitic gneiss with an influence of loess and volcanic ash in upper part
Mean annual precipitation--about 380 mm
Mean annual air temperature--about 9 degrees C
Depth class--shallow
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Ultic Haploxerolls
TYPICAL PEDON: Swakane cobbly ashy loam in an area of native range vegetation, on a 45-percent, south-facing slope at an 830 m
A1--0 to 15 cm; cobbly ashy loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; common fine tubular pores; 15 percent gravel and 10 percent cobbles; neutral (pH 6.6); clear wavy boundary
A2--15 to 28 cm; very gravelly ashy loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; common fine roots; common fine tubular and interstitial pores; 40 percent gravel and 15 percent cobbles; neutral (pH 6.8); clear wavy boundary
2C--28 to 36 cm; extremely gravelly sandy loam, brown (10YR 5/3) dry, dark brown (10YR 3/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; few fine roots; common fine tubular and irregular pores; 45 percent gravel and 15 percent cobbles; neutral (pH 7.0); gradual wavy boundary
2R--36 cm; unweathered granite
TYPE LOCATION: Colville Indian Reservation, Okanogan County, Washington; about 9.5 km east of the Colville Indian Agency; about 305 m west and 30 m north of the southeast corner of section 1, T. 30 N., R. 31 E.; latitude 48.1252823, longitude -118.8460617, datum WGS 84 (coordinates estimated from PLSS details)
RANGE IN CHARACTERISTICS:
Depth to diagnostic horizons and other features are measured from the top of the first mineral layer.
Mean annual soil temperature--8 to 11 degrees C
Moisture control section--dry in all parts to lithic contact 90 to 105 days after summer solstice (July to September); moist in October through June
Depth to hard bedrock--25 to 50 cm
Recent (1980) volcanic ash layer--6 to 18 mm thick; in some pedons between organic layer and mineral soil surface
Base saturation--50 to 75 percent (by sum of cations)
Thickness of layers influenced by volcanic ash--18 to 30 cm
Estimated properties of layers influenced by volcanic ash
*Content of volcanic glass in the 0.02- to 2-mm fraction--5 to 20 percent
*Acid oxalate Al plus 1/2 Fe--0.4 to 1.0 percent
*Moist bulk density--1.0 to 1.2 g/cm3
Particle-size control section
*Content of clay--5 to 15 percent
*Content of medium and coarse sand--25 to 55 percent
*Content of rock fragments--35 to 70 percent
A horizon
*Value--4 or 5 dry, 2 or 3 moist
*Chroma--2 to 4 dry, 1 to 3 moist
*Texture--ashy loam, ashy fine sandy loam, ashy sandy loam
*Content of clay--5 to 15 percent
*Content of gravel--10 to 40 percent
*Content of cobbles--0 to 15 percent
*Content of stones and boulders--0 to 10 percent
*Reaction--5.6 to 7.3
*Combined thickness--5 to 40 cm
An AB or Bw horizon is in some pedons.
2C horizon (where present)
*Hue--10YR, 2.5Y, multicolored
*Value--4 to 7 dry, 3 to 5 moist
*Chroma--2 to 4 dry or moist
*Texture--loam, sandy loam, loamy sand, coarse sandy loam
*Content of clay--5 to 15 percent
*Content of gravel--20 to 60 percent
*Content of cobbles--0 to 25 percent
*Content of stones--0 to 10 percent
*Reaction--5.6 to 7.8
*Thickness--0 to 30 cm
COMPETING SERIES:
Brisky--dry 75 to 90 days; 35 to 50 percent sandstone rock fragments in particle-size control section
Witzel--hue of 7.5YR or 5YR; more than 18 percent clay in particle-size control section
GEOGRAPHIC SETTING:
Elevation--335 to 1495 m
Climate--warm, dry summers; cool, moist winters
Mean annual precipitation--305 to 585 mm
Mean January air temperature--about -3 degrees C
Mean July air temperature--about 21 degrees C
Mean annual air temperature--about 9 degrees C
Frost-free season--100 to 165 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Conconully--more than 50 cm deep to lithic contact; on undulating ground moraines and foothills
Dinkelman--more than 50 cm deep to lithic contact; on footslopes and side slopes
Donavan--more than 50 cm deep to lithic contact
Ginnis--more than 50 cm deep to lithic contact; on footslopes, backslopes, and shoulders of hills
Skanid--25 to 50 cm deep to weathered granitic rock; on mountains
Spokane--more than 50 cm deep to lithic contact; on foothills, mountains, and ridgetops
Tyee--25 to 50 cm deep to weathered granitic rock; on mountain side slopes
Vanbrunt--more than 50 cm deep to lithic contact; on mountain ridges, shoulders, and backslopes
Wynhoff--more than 50 cm deep to lithic contact; on shoulders, backslopes, and footslopes of hills and mountains
DRAINAGE AND PERMEABILITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high
USE AND VEGETATION:
Use--livestock grazing, wildlife habitat, homesite development, watershed
Potential natural vegetation--bluebunch wheatgrass, Sandberg bluegrass, arrowleaf balsamroot, Wyeth eriogonum, snow eriogonum, common yarrow, antelope bitterbrush, widely spaced stunted ponderosa pine
DISTRIBUTION AND EXTENT: North-central and northeastern Washington; MLRA 6; moderate extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Colville Indian Reservation, Okanogan County, Washington; 1987
REMARKS:
Diagnostic horizons and other features in this pedon
*Mollic epipedon--zone from 0 to 28 cm
*Vitrandic feature--zone from 0 to 28 cm
*Depth to lithic contact--36 cm
*Particle-size control section--zone from 0 to 36 cm
*Estimated base saturation (sum of cations)--50 to 75 percent
6/2016--This official series description (OSD) was updated as part of the final correlation of the Spokane County, Washington, soil survey. The formatting was updated according to SSR1 Technical Note 11--Content and Format of Official Series Descriptions (revised 12/2015).
National Cooperative Soil Survey
U.S.A.