LOCATION DRAGOON                 WA

Established Series
Rev. NCD/SHB/EMM
04/2011

DRAGOON SERIES

The Dragoon series consists of moderately deep to a paralithic contact, well drained soils formed in residuum and colluvium from granitic rocks, gneiss, or schist and a thin mantle of loess and volcanic ash. They are on mountain slopes and foothills. Slopes range from 0 to 90 percent. The average annual precipitation is 15 to 21 inches. The mean annual temperature is 47 degrees F.

TAXONOMIC CLASS: Fine-loamy, isotic, mesic Vitrandic Argixerolls

TYPICAL PEDON: Dragoon ashy silt loam - cultivated. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 6 inches; dark grayish brown (10YR 4/2) ashy silt loam, very dark brown (10YR 2/2) moist; weak medium granular structure; slightly hard, friable, slightly sticky and plastic; common fine roots; neutral (pH 6.6); clear wavy boundary. (6 to 10 inches thick)

A--6 to 11 inches; grayish brown (10YR 5/2) ashy silt loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common fine roots; few fine pores; neutral (pH 6.6); clear wavy boundary. (4 to 8 inches thick)

AB--11 to 16 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; massive; slightly hard, very friable, non sticky and nonplastic; common fine roots; few fine pores; neutral (pH 6.6); clear smooth boundary. (4 to 8 inches thick)

Bt--16 to 23 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky; hard, firm, slight sticky and slightly plastic; few fine roots; few fine pores; few faint clay films on faces of peds; 10 percent gravel; neutral (pH 6.6); clear wavy boundary. (5 to 12 inches thick)

2Cr--23 to 60 inches; disintegrated granite; massive, but crumbles readily into fine gravel and coarse sand.

TYPE LOCATION: Lincoln County, Washington; about 1,280 feet south and 1,120 feet east of the northwest corner of section 2 T. 26 N., R 37 E..Latitude - 47 degrees, 47 minutes, 4.7 seconds N.,; Longitude - 118 degrees, 6 minutes, 53.5 seconds W.; NAD 83. USGS quadrangle; Benjamin Lake, WA.

RANGE IN CHARACTERISTICS: Solum thickness and depth to a paralithic contact is 20 to 40 inches. These soils are usually moist, but are dry in all parts between depths of 4 and 12 inches for 60 to 75 consecutive days following the summer solstice. The upper 7 to 14 inches has an estimated volcanic glass content of 5 to 20 percent and an acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.4 to 1.0 percent. Mean annual soil temperature at a depth of 20 inches is estimated to be 47 to 52 degrees F. The mollic epipedon is 10 to 18 inches thick. The control section has 0 to 15 percent coarse fragments. The soils are slightly acid or neutral throughout. Some pedons have stony or very stony surface layers.

The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 moist and dry.

The Bt horizon has hue of 7.5YR or 10YR, value of 4 to 6 dry, 3 or 4 moist, and chroma of 3 or 4. It is heavy silt loam, heavy loam, sandy clay loam, or light clay loam.

Some pedons have a B3 or C horizon of very gravelly or gravelly loamy sand or sandy loam.

COMPETING SERIES: These are the Gibbs and Glenrose series. The Gibbs soils are moderately deep to a lithic contact. The Glenrose soils are very deep.

GEOGRAPHIC SETTING: Dragoon soils are on foothills, ridgetops, and mountain side slopes at elevations of 2,000 to 3,000 feet. Slopes are 0 to 90 percent. These soils formed in material weathered from granitic rocks, gneiss, or schist and have a thin mantle of volcanic ash and loess. These soils occur in a continental climate with dry summers and cool, moist winters. Average annual precipitation is 15 to 21 inches, average January temperature is 25 degrees F, average July temperature is 68 degrees F, and mean annual temperature is 45 to 49 degrees F. The frost-free season is 100 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Spokane and Tucannon soils. Spokane soils are hills and do not have an argillic horizon and are coarse-loamy in the particle size control section. Tucannon soils are on basalt plateaus and do not have an argillic horizon and are fine-silty in the particle size control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Used for woodland, cropland, watershed, wildlife habitat and recreation. Cultivated areas are used for the production of small grains and alfalfa. Native vegetation is ponderosa pine and Douglas-fir, with an understory of Idaho fescue, bluebunch wheatgrass, Sandberg bluegrass, and arrowleaf balsamroot.

DISTRIBUTION AND EXTENT: Eastern Washington. MLRA 9 and 43A, 44A. Series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Spokane County, Washington, 1964.

REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 11 inches, an argillic horizon from 11 to 27 inches, and a paralithic contact at 27 inches. Estimated base saturation (sum of cations) is less than 75 percent in some part of the upper 30 inches.

The type location was moved from Spokane County to Lincoln County in 2011 because the Dragoon soils in Spokane County were correlated to other soils such as Morical. The Morical series mapped in Spokane is in non-forested areas and has an assumed mixed mineralogy.

MLRA update notes: Dragoon in the Cashmere Mountains Area, Stevens and Lincoln counties should be investigated as to the extent of the volcanic ash influence (vitrandic subgroup or not) and mineralogy (mixed vs. isotic). Dragoon should also be investigated as to which MLRAs it occurs in.

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National Cooperative Soil Survey
U.S.A.