LOCATION WETACHE OR
Tentative Series
IRD. AGG/KLM/MPR
02/2025
WETACHE SERIES
Landscape--Eastern Cascade mountains
Landform--moraines, glaciated mountain slopes
Slope--0 to 50 percent
Parent Material--volcanic ash mixed with till
Mean annual precipitation--around 1200 mm
Mean annual air temperature--5.5 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy, amorphic, frigid Humic Udivitrands
TYPICAL PEDON: Wetache ashy sandy loam, forested, on an east-facing, 18 percent slope at an elevation of 1252 meters. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2 centimeters; slightly decomposed plant material, very dark grayish brown (10YR 3/2); strongly acid (pH 5.5); abrupt smooth boundary
A1--2 to 11 centimeters; ashy sandy loam, brown (10YR 4/3), very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; very friable, nonsticky, nonplastic; many fine roots ; many very fine irregular pores; 5 percent subrounded gravel; neutral (pH 6.6); gradual smooth boundary
A2--11 to 52 centimeters; ashy sandy loam, brown (10YR 5/3), dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; very friable, nonsticky, nonplastic; common fine and medium and few coarse roots; many very fine irregular pores; 10 percent subrounded gravel; neutral (pH 6.7); gradual smooth boundary
Bw1--52 to 78 centimeters; gravelly ashy sandy loam, brown (10YR 5/3), dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; friable, nonsticky, nonplastic; few fine roots; many very fine irregular pores; 20 percent gravel and 5 percent subrounded cobbles; neutral (pH 6.9); clear smooth boundary
Bw2--78 to 98 centimeters; gravelly ashy loamy sand, brown (10YR 5/3), dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; friable, nonsticky, nonplastic; few coarse, medium, and fine roots ; many very fine irregular pores; 15 percent subrounded gravel and 10 percent subrounded cobbles; neutral (pH 7.0); clear smooth boundary
BC--98 to 105 centimeters; very gravelly ashy loamy sand, pale brown (10YR 6/3), dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; friable, nonsticky, nonplastic; few medium and fine roots; many very fine irregular and few fine tubular pores; 30 percent subrounded gravel and 20 percent subrounded cobbles; neutral (pH 7.0); clear smooth boundary
C--105 to 200 centimeters; extremely cobbly ashy loamy sand, pale brown (10YR 6/3), very dark grayish brown (10YR 3/2) moist;single grain; nonsticky, nonplastic; many very fine irregular and few fine tubular pores; 15 percent subrounded gravel and 70 percent subrounded cobbles; neutral (pH 7.0)
TYPE LOCATION: Deschutes County, Oregon; latitude 44.3679220, longitude -121.7562670, datum WGS84 (coordinates determined with a GPS).
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 .5degrees C
Soil Moisture--moist in winter and spring, dry in the moisture control section for less than 45 consecutive days in the 4 months following the summer solstice.
Thickness of umbric epipedon--25 to 50 cm
Depth to till--75 to over 100 cm
Reaction--pH 6.1 to 7.3 (slightly acid to neutral)
Thickness of surface ash influenced layers--90 to over 100 cm
Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + Fe--0. to 2.0 percent
*0.02 to 2.0 mm fraction--50 to 90 percent
*Volcanic glass in the 0.02 to 2.0 mm fraction--50 to 80 percent
*P retention--40 to 80 percent
*1500 kPa water retention--less than 15 percent
*8Si + 2Fe (aox)--5 to 30 percent
*8Si - 2Fe (aox)--4 to 25 percent
Particle-size control section: mineral surface to 100 cm below mineral surface
*clay content, weighted average--1 to 4 percent
*rock fragment content, weighted average--2 to 35 percent
A1 horizon
*Value--2 or 3 moist, 4 dry
*Chroma--1 to 3
*Fine earth texture--ashy sandy loam, ashy loamy sand, ashy loamy coarse sand
*Clay--1 to 8 percent
*Sand--55 to 90 percent
*Organic matter--2 to 5 percent
*Gravel--0 to 15 percent
*Reaction-- pH 6.1 to 6.5 (slightly acid)
*Thickness--thickness of A1 horizon is 8 to 20 cm
A2 horizon
*Value--2 or 3, 4 or 5 dry
*Chroma--2 or 3
*Fine earth texture--ashy sandy loam, ashy loamy sand, ashy loamy coarse sand
*Clay--1 to 8 percent
*Sand--55 to 90 percent
*Organic matter--1.5 to 3 percent
*Gravel--0 to 20 percent
*Reaction--pH 6.1 to 7.3 (slightly acid to neutral)
*Thickness--thickness of A2 horizon is 15 to 45 cm
Bw1 horizon
*Value--2 or 3
*Chroma--2 to 4
*Fine earth texture--ashy sandy loam, ashy loamy sand, ashy loamy coarse sand
*Clay--1 to 8 percent
*Sand--55 to 90 percent
*Organic matter--0.50 to 1 percent
*Total rock fragment content--0 to 30 percent
*Gravel--0 to 30 percent
*Cobble--0 to 10 percent
*Reaction--pH 6.1 to 7.3 (slightly acid to neutral)
*Thickness--thickness of Bw1 horizon is 20 to 40 cm
Bw2 horizon
*Hue--10YR or 7.5YR
*Chroma--3 or 4
*Fine earth texture--ashy sandy loam, ashy loamy sand
*Clay--1 to 8 percent
*Sand--55 to 90 percent
*Organic matter--0.25 to 0.75 percent
*Total rock fragment content--0 to 60 percent
*Gravel--0 to 30 percent
*Cobble--0 to 30 percent
*Reaction--pH 6.6 to 7.3 (neutral)
*Thickness--thickness of Bw2 horizon is 20 to 45 cm
BC horizon
*Value--3 to 5
*Chroma--2 to 4, moist or dry
*Fine earth texture--ashy sandy loam, ashy loamy sand
*Clay--1 to 5 percent
*Sand--55 to 90 percent
*Organic matter--0.1 to 0.75 percent
*Total rock fragment content--15 to 85 percent
*Gravel--10 to 50 percent
*Cobble--5 to 35 percent
*Reaction--pH 6.6 to 7.3 (neutral)
*Thickness--thickness of BC horizon is 7 to 75 cm
C horizon
*Value--3 to 5
*Chroma--2 to 4, moist or dry
*Fine earth texture--ashy sandy loam, ashy loamy sand*Clay--1 to 5 percent
*Sand--55 to 90 percent
*Organic matter--0.1 to 0.75 percent
*Total rock fragment content--25 to 85 percent
*Gravel--10 to 75 percent
*Cobble--10 to 75 percent
*Reaction--pH 6.6 to 7.3 (neutral)
*Thickness--thickness of C horizon is 40 to 100 cm
COMPETING SERIES:
None
GEOGRAPHIC SETTING:
Elevation--1000 to 1650 meters
Slope--0 to 50 percent
Climate--cool, wet winters and warm, moist summers
Mean annual precipitation--1020 to 1520 mm
Mean annual air temperature--4.5 to 6.5 degress C
Frost-free period--40 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Dryache--occurs on similar geomorphic positions; greater than 45 dry days following the summer solstice
Sanagon--occurs on summits and shoulder slopes of moraines; greater than 35 percent fragments in the particle size control section
Skelwa--occurs on outwash plains; greater than 35 percent fragments in the particle size control section
Howash--occurs on mountain slopes; greater than 35 percent fragments in the particle size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage--well drained
Saturated hydraulic conductivity (Ksat)--high to very high in all horizons
USE AND VEGETATION:
Use--wildlife habitat, recreation, timber production
Vegetation--grand fir, white fir, Douglas-fir, ponderosa pine, snowbrush ceanothus, greenleaf manzanita, golden chinquapin, princes pine, starflower, rattlesnake plantain, western fescue, pinegrass, bracken fern, nevada pea, American vetch, lupine
Typical USFS Plant Association--ABCO-ABGR/TRLA2 (white fir-grand fir/western starflower)
DISTRIBUTION AND EXTENT:
East slopes of the Cascade Mountains in central Oregon; MLRA 6; minor extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED:
Deschutes County, Deschutes National Forest, Oregon 2023; the name is derived from Cache mountain, a nearby landscape feature.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
*Particle-size control section--2 to 102 cm
*Umbric epipedon--2 to 52 cm
*Andic soil properties--2 to 200 cm
Laboratory data inferred from geographically associated Belrick series from (Pedon#: 84P0811). This data is available from the NRCS-NSSC-Kellogg Soil Survey Laboratory, Lincoln, Nebraska.
The volcanic ash deposit is from the eruption of Mt. Mazama (7.7 kya). There may be some areas with additional deposits from the Sand Mountain eruption (between 3 and 4 kya).
National Cooperative Soil Survey
U.S.A.