LOCATION DILLCOURT               WA

Established Series
Rev. EH/RJE/RWL
09/2019

DILLCOURT SERIES

Landscape--canyonlands
Landform--canyons
Slope--30 to 75 percent
Parent material--loess over colluvium derived from basalt mixed with loess
Mean annual precipitation--about 580 mm
Mean annual air temperature--about 9 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Pachic Argixerolls

TYPICAL PEDON: Dillcourt very cobbly loam in an area of rangeland, on a 55-percent, southwest-facing slope at an elevation of 370 m

A1--0 to 30 cm; very cobbly loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots; many fine irregular pores; 15 percent gravel and 30 percent cobbles; 1 percent stones on surface; slightly acid (pH 6.2); gradual wavy boundary

A2--30 to 56 cm; very gravelly loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; many fine and medium irregular pores; 30 percent gravel and 10 percent cobbles; moderately acid (pH 6.0); gradual wavy boundary

Bt1--56 to 94 cm; very cobbly loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common fine and medium tubular pores; common distinct clay films on faces of peds and in pores; 15 percent gravel and 35 percent cobbles; slightly acid (pH 6.2); clear wavy boundary

Bt2--94 to 150 cm; very cobbly clay loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and moderately plastic; common very fine roots; common fine tubular pores; many distinct clay films on faces of peds and in pores; 20 percent gravel and 30 percent cobbles; moderately acid (pH 5.8)

TYPE LOCATION: Klickitat County, Washington, about 21 km northwest of Goldendale; about 490 m north and 30 m west of the southeast corner of section 31, T. 5 N., R. 14 E.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--8 to 10 degrees C
Moisture control section--usually moist, but dry 75 to 90 consecutive days following summer solstice
Particle-size control section--18 to 35 percent clay and 35 to 65 percent rock fragments (weighted average)
Thickness of mollic epipedon--50 to 66 cm
Reaction--5.6 to 6.5 throughout
Estimated base saturation (by sum)--more than 75 percent throughout upper 75 cm

A horizon
Value--3 to 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Texture--very cobbly loam, very gravelly loam
Combined thickness--46 to 61 cm

Bt horizon
Hue--7.5YR, 10YR
Value--4 or 5 dry, 3 or 4 moist
Chroma--4 to 6 dry or moist
Texture--very cobbly silt loam, very cobbly loam, very cobbly clay loam
Clay films--faint to distinct
Thickness of Bt1 horizon--36 to 41 cm

COMPETING SERIES:
Copperfield--100 to 150 cm or more (deep, very deep) to a lithic contact (basalt); dry 60 to 80 consecutive days following summer solstice; top of argillic horizon at a depth of 100 to 125 cm
Hyrum--dry 60 consecutive days following summer solstice; solum 76 to 114 cm thick; slightly rounded and angular fragments of sandstone, quartzite, and limestone in particle-size control section
Jadpor--dry 115 to 125 consecutive days following summer solstice
Kettenbach, Ricketts--50 to 100 cm (moderately deep) to a lithic contact (basalt)
Sagley--100 to 150 cm (deep) to a lithic contact (basalt); mollic epipedon 102 to 127 cm thick

Soils that have similar classification
Carrcreek--no volcanic ash influence in upper part that meets criteria for Vitrandic subgroup; mean annual soil temperature of 11 to 15 degrees C

GEOGRAPHIC SETTING:
Elevation--120 to 850 m
Climate--warm, dry summers; cool, moist winters
Mean annual precipitation--460 to 640 mm
Mean January air temperature--about -2 degrees C
Mean July air temperature--about 19 degrees C
Mean annual air temperature--about 8 to 9 degrees C
Frost-free season--100 to 140 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Gunn--on plateaus; fine-loamy particle-size class; ochric epipedon
Legall, Oreoke--on canyon slopes; base saturation (by sum of cations) less than 75 percent in some part of upper 75 cm
Leidl--on canyon slopes and plateaus; base saturation (by sum of cations) less than 75 percent in some part of upper 75 cm

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high

USE AND VEGETATION:
Use--mainly livestock grazing and wildlife habitat
Native vegetation--bluebunch wheatgrass, arrowleaf balsamroot, Sandberg bluegrass, Cusick's biscuitroot, velvet lupine

DISTRIBUTION AND EXTENT: Klickitat County, Washington; MLRA 8; small extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Klickitat County, Washington; 2003

REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Mollic epipedon--zone from the surface to a depth of 56 cm
*Argillic horizon--zone from 56 to 150 cm
*Estimated base saturation (by sum)--more than 75 percent in upper 75 cm

Further study is needed to differentiate the Dillcourt series from the Oreoke series, which is in a transitional zone between areas of rangeland and forestland. The Oreoke series is correlated to the Oregon white oak/antelope bitterbrush/Idaho fescue plant community.

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National Cooperative Soil Survey
U.S.A.