LOCATION COUGARROCK              OR

Established Series
Rev. JLW/RAW/DAL
10/2012

COUGARROCK SERIES

The Cougarrock series consists of moderately deep, well drained soils on backslopes of mountains. Cougarrock soils formed in volcanic ash mixed with colluvium overlying residuum weathered from andesitic tuff breccia or basalt. Slopes are 0 to 60 percent. Mean annual precipitation is about 26 inches and mean annual temperature about 40 degrees F.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Vitrandic Haploxeralfs

TYPICAL PEDON: Cougarrock ashy silt loam forested, on a 27 percent north-facing slope at an elevation of 5,045 feet. (Colors are for moist soil unless otherwise noted. Soil textures are apparent field textures.)

Oi--0 to 1 inch; slightly decomposed grasses, needles, twigs and logs

Oe--1 to 2 inches; moderately decomposed forest litter and logs

A--2 to 7 inches; dark brown (7.5YR 3/3) ashy silt loam, brown (7.5YR 5/3) dry; weak medium subangular blocky structure parting to weak fine angular and very fine subangular blocky; soft, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine and fine irregular pores; 2 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (3 to 5 inches thick)

Bw--7 to 15 inches; brown (7.5YR 4/2) ashy silt loam, pinkish gray (7.5YR 6/2) dry; weak medium subangular blocky structure parting to weak fine subangular blocky; soft, very friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; common very fine and few fine tubular, and common very fine irregular pores; 5 percent gravel; slightly acid (pH 6.5); abrupt wavy boundary. (6 to 10 inches thick)

2Eb--15 to 19 inches; brown (7.5YR 4/4) very gravelly clay loam, light yellowish brown (10YR 6/4) dry; weak fine angular and very fine subangular blocky structure; hard, friable, slightly sticky and moderately plastic; common very fine, and few fine and medium roots; common very fine and fine tubular, and common very fine irregular pores; 30 percent gravel, and 10 percent cobbles; neutral (pH 7.0); clear wavy boundary. (4 to 9 inches thick)

2Btb--19 to 34 inches; yellowish brown (10YR 5/4) very gravelly clay loam, brown (7.5YR 5/4) dry; moderate fine angular and very fine angular blocky structure; very hard, very firm, moderately sticky and moderately plastic; few faint clay films on ped faces; common very fine and few fine roots; common very fine and few fine irregular, and few very fine tubular pores; 40 percent gravel and 15 percent cobbles; neutral (pH 6.8); abrupt irregular boundary. (8 to 18 inches thick)

2Cr--34 to 39 inches; fractured soft tuff

2R--39 inches; hard tuff

TYPE LOCATION: Grant County, Oregon
Section 25 (SE1/4, NW1/4, NW1/4), T. 8 S., R. 35 E.
Latitude: 44 degrees, 50 minutes, 49.6 seconds N.
Longitude: 118 degrees, 27 minutes, 45.6 seconds W.
UTM coordinates: zone 11; north 4966790.0 meters, east 384410.0 meters; NAD27
USGS Quadrangle: Granite

RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 41 to 44 degrees F
Mean Summer Soil Temperature: 49 to 52 degrees F
Mean Winter Soil Temperature: 34 to 36 degrees F
Soil Moisture: xeric regime, dry 45 to 60 consecutive days in summer

Particle-size Control Section: upper 20 inches of argillic horizon or to bedrock contact
clay content, average: 36 to 39 percent
rock fragment content, average: 46 to 70 percent

Diagnostic Horizons and Features:
vitrandic subgroup properties: upper boundary at the mineral surface; 8 to 14 inches thick
Al+1/2Fe (ammonium oxalate): 0.4 to 0.9 percent
P retention: 25 to 50 percent
0.02-2.0 mm fraction: 30 to 40 percent of fine earth
glass content in the 0.02-2.0mm fraction: 15 to 30 percent
cambic horizon: 3 to 11 inches thick
argillic horizon: 8 to 18 inches thick
lithic contact, depth below mineral soil surface: 20 to 40 inches

A horizon:
color, moist: 5YR 2.5/1, 3/1, 3/2; 7.5YR 3/2, 3/3; 10YR 3/2
color, dry: 5YR 4/3, 5/2; 7.5YR 4/2, 5/2, 5/3, 6/3
texture: ASHY-SIL, GR- ASHY-SIL, CB- ASHY-SIL
clay content: 12 to 17 percent
rock fragment content: 2 to 25 percent
gravel: 2 to 20 percent
cobbles: 0 to 10 percent
stones: 0 to 2 percent
reaction: moderately acid to neutral; pH: 5.6 to 7.3

Bw horizon:
color, moist: 5YR 3/4; 7.5YR 3/4, 4/2; 10YR 4/3
color, dry: 5YR 5/3; 7.5YR 5/2, 6/2, 6/3, 6/4; 10YR 5/3, 6/2
texture: ASHY-SIL, ASHY-L, GR-ASHY-L, CB-ASHY-L, CB-ASHY-SIL
clay content: 10 to 24 percent
rock fragment content: 5 to 30 percent total
gravel: 5 to 25 percent
cobbles: 0 to 10 percent
stones: 0 to 2 percent
reaction: moderately acid to neutral; pH: 5.6 to 7.3

2Eb horizon; may include 2EBb in some pedons:
color, moist: 7.5YR 4/3, 4/4, 5/3; 10YR 4/3
color, dry: 5YR 6/2, 6/3; 7.5YR 5/2, 5/3, 5/4, 6/2; 10YR 6/3, 6/4
texture: GRV-CL, GRV-L, CB-L, CBV-CL, GR-L, STV-L
clay content: 26 to 32 percent
rock fragment content: 25 to 45 percent total
gravel: 15 to 35 percent
cobbles: 5 to 20 percent
stones: 0 to 10 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3

2Btb horizon:
color, moist: 7.5YR 3/4, 4/2, 4/3, 5/6; 10YR 3/4, 4/3, 4/4, 5/3, 5/4
color, dry: 5YR 5/3; 7.5YR 5/3, 5/4, 5/6, 6/2; 10YR 5/3
texture: STV-CL, GRV-CL, CBV-CL, CBX-CL, STX-CL, GRX-CL, GRV-C
clay content: 35 to 42 percent
rock fragment content: 35 to 70 percent total
gravel: 20 to 55 percent
cobbles: 5 to 30 percent
stones: 0 to 25 percent
reaction: neutral; pH: 6.6 to 7.3

Cr horizon: soft tuff, 3 to 10 inches thick

COMPETING SERIES:
Cotay: moderately deep (20 to 40 inches) to a lithic contact (metavolcanic, serpentine); does not have a paralithic contact above a lithic contact; cambic (Bw) is silt loam with 6 to 22 percent clay; have a buried eluvial (2Eb) horizon; rock fragments are angular in shape
Dunstan: deep (40 to 60 inches) to a lithic contact (andesitic tuff breccia)
Stithum: very deep (lacks a lithic contact within 60 inches) formed in alluvium (mixed lithology); do not have a cambic (Bw) horizon; dry 60 to 75 consecutive days in summer
Tamarackcanyon: moderately deep (20 to 40 inches) to a lithic contact (basalt); cambic (Bw) is clay loam or silty clay loam with 25 to 35 percent clay; do not have an eluvial (2Eb) horizon

GEOGRAPHIC SETTING:
Landform: surface eroding mountain backslope of relict andesitic-tuff breccia mudflows
Slope gradient: 0 to 60 percent
Parent material: Mazama volcanic ash mixed with colluvium overlying residuum
Lithology: andesitic tuff breccia
Elevation: 4,100 to 5,100 feet
Climate: cold, wet winters; warm, dry summers
Mean annual precipitation: 23 to 29 inches
Mean annual air temperature: 39 to 41 degrees F.
Frost-free period: 40 to 75 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Btree: on stable mountain concave slopes; deep to tuff; thick ash mantle over buried argillic horizon; under grand fir, lodgepole pine, western larch, Douglas-fir, twinflower, prince's pine, sidebells pyrola, roundleaf violet, pinegrass and northwestern sedge
Dunstan: on eroding backslopes; deep to andesitic tuff breccia with a mantle of mixed volcanic ash and colluvium, over clayey-skeletal argillic horizon; under grand fir, lodgepole pine, grouse huckleberry, pinegrass and elk sedge
Grubcreek: on convex to planar, mid to upper, erosional summits and benches; moderately deep without an argillic, under grand fir, Douglas-fir, ponderosa pine, common snowberry, elk sedge and pinegrass
Hafmau: on rolling mountain sideslopes and benches; shallow to bedrock with an argillic horizon, under Douglas-fir, ponderosa pine, elk sedge and heartleaf arnica
Kamela: on ridge crests and shoulder slopes; moderately deep to basalt with a mixed mantle of ash and loess over loamy-skeletal colluvium; under grand fir, Douglas-fir, ponderosa, rocky mountain maple, ninebark, heartleaf arnica and princes pine.
Sharpridge: on lower backslopes, footslopes and toeslopes; deep to hard tuff, with volcanic ash mantle 14 to 18 inches thick and argillic horizon; under grand fir, Douglas-fir, western larch, big huckleberry, darkwoods violet and western fescue

DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderately rapid over slow

USE AND VEGETATION:
Use: timber production, recreation, livestock grazing, wildlife habitat, watershed
Potential native vegetation: Grand fir, lodgepole pine, western larch, Douglas-fir, ponderosa pine, big huckleberry, grouse huckleberry, birchleaf spiraea, common snowberry, Cusicks peavine, blueleaf strawberry, fireweed, common yarrow, big flowered sandwort, yellow hawkweed, pinegrass, elk sedge, northwestern sedge.
Plant association: ABGR/VASC (grand fir/grouse huckleberry); may include: PICO(ABGR)/VASC (lodgepole pine (grand fir)/grouse huckleberry), PICO(ABGR)/VASC/CARU (lodgepole pine (grand fir)/grouse huckleberry/pinegrass), ABGR/VAME (grand fir/big huckleberry) or ABGR/SPBE (grand fir/birchleaf spiraea). Dry phase: PSME/SYAL (Douglas-fir/common snowberry) or PSME/CARU (Douglas-fir/pinegrass)

DISTRIBUTION AND EXTENT:
Distribution: MLRA: 10; Central Rocky and Blue Mountain Foothills
Extent: moderate

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

SERIES ESTABLISHED: Wallowa-Whitman National Forests, Oregon, 2012

REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon: 2 to 7 inches; A horizon
cambic horizon: 7 to 15 inches; Bw horizon
eluvial horizon, buried: 15 to 19 inches; 2Eb horizon
argillic horizon: 19 to 34 inches; 2Btb horizon
andic soil properties (mixed ash mantle): 2 to 15 inches; A, Bw horizon
particle-size control section: 19 to 34 inches; 2Btb horizon
paralithic material: 34 to 39 inches; 2Cr horizon

ADDITIONAL DATA: Laboratory data: National Soil Survey Laboratory, Lincoln, NE; pedon ID: 97OR023001, sampled as Cougarrock series

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National Cooperative Soil Survey
U.S.A.