LOCATION WASHBOARD COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Mollic Haplocryalfs
TYPICAL PEDON: Washboard gravelly loam, on a west facing, 62 percent mountain backslope under spruce-fir woodland at an elevation of 8,300 feet. (colors are for dry soil unless otherwise noted. When described on September 7, 1987, the soil was moist in some parts.)
Oi--0 to 1 inch; mat of slightly decomposed needles, twigs, and leaves (0 to 3 inches thick)
A1--1 to 7 inches; dark reddish gray (5YR 4/2) gravelly loam, dark reddish brown (5YR 3/3) moist; moderate fine subangular blocky structure parting to moderate fine granular; soft, very friable, nonsticky and slightly plastic; 20 percent gravel; slightly acid (pH 6.4); clear wavy boundary.
A2--7 to 13 inches; reddish brown (5YR 5/4) very gravelly loam, reddish brown (5YR 4/3) moist; moderate fine subangular blocky structure parting to moderate fine granular; soft, very friable, nonsticky and slightly plastic; 25 percent gravel, 10 percent cobbles; neutral (pH 6.6); clear wavy boundary. (combined thickness of the A horizons is 6 to 15 inches)
BEt--13 to 24 inches; weak red (2.5YR 6/4) very gravelly sandy clay loam, dusky red (2.5YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, firm, sticky and slightly plastic; common faint clay films on faces of peds; 50 percent gravel, 5 percent cobbles; slightly acid (pH 6.2); clear wavy boundary. (0 to 13 inches thick)
Bt1--24 to 43 inches; yellowish red (5YR 4/6) very cobbly clay loam, dark reddish brown (5YR 3/4) moist; strong fine and medium subangular blocky structure; hard, very firm, sticky and plastic; many distinct clay films on faces of peds; 25 percent gravel, 20 percent cobbles, 10 percent stones; slightly acid (pH 6.4); clear wavy boundary.
Bt2--43 to 66 inches; yellowish red (5YR 4/6) extremely stony clay loam, dark reddish brown (5YR 3/4) moist; strong fine and medium subangular blocky structure; hard, very firm, sticky and plastic; many distinct clay films on faces of peds; 15 percent gravel, 60 percent stones; neutral (pH 6.6). (combined thickness of the Bt horizon is 30 to 60 inches)
TYPE LOCATION: Ouray County, Colorado; about 7 miles east of Ridgway, Colorado; within an unsectionized area of the Uncompahgre National Forest estimated to be in Section 27, T. 45 N., R. 7 W. USGS Wetterhorn Peak topographic quadrangle; Latitude: 38 degrees, 07 minutes, 05 seconds north; Longitude: 107 degrees, 37 minutes, 21 seconds west, NAD 1927.
RANGE IN CHARACTERISTICS:
Depths in this section are measured from the top of the mineral soil surface.
Soil moisture regime: udic; dry for less than 30 days in summer.
Mean annual soil temperature: 36 to 47 degrees F.
Depth to the top of argillic horizon: 6 to 23 inches.
Particle-size control section:
Clay content: 22 to 35 percent
Rock fragment content: 35 to 80 percent
A horizon:
Hue: 5YR to 10YR
Value: 4 or 5 dry, 3 or 4 moist, 3 or less moist in the upper 6 inches when mixed
Chroma: 2 to 4 dry or moist
Texture: GR-L, GRV-L
Rock fragments: andesite, rhyolite, breccia, or tuff. 20 to 40 percent total rock fragments; 15 to 30 percent gravel, 0 to 15 percent cobbles, 0 to 5 percent stones.
Reaction: slightly acid (pH 6.1) to neutral (pH 7.3)
BEt horizon (not present in all pedons):
Hue: 2.5YR to 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 or 5 dry or moist
Texture: GRV-SCL, CBV-L, GR-SL, CBV-SCL
Rock fragments: andesite, rhyolite, breccia, or tuff. 30 to 55 percent total rock fragments; 20 to 50 percent gravel, 0 to 35 percent cobbles, 0 to 10 percent stones.
Reaction: slightly acid (pH 6.1) to neutral (pH 7.3)
Bt horizon:
Hue: 5YR to 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 4 to 6 dry or moist
Texture: CBV-CL, STV-CL, STX-CL, CBV-SCL, STX-SCL
Rock fragments: andesite, rhyolite, breccia, or tuff. 35 to 80 percent total rock fragments; 10 to 25 percent gravel, 0 to 30 percent cobbles, 10 to 60 percent stones.
Base saturation: 80 to 100 percent
Reaction: slightly acid (pH 6.1) to neutral (pH 7.3)
COMPETING SERIES: These are the Buffmeyer, Condie, Jonda, Judkins, Mulgon, Namon, Rocko, Timberlin, and Wapshilla series. In addition the Guiser, Scandard, and Tamred series may be competitors when they are reclassified. The Buffmeyer soils have less than 22 percent clay in the particle-size control section. The Condie, Guiser, and Rocko soils are dry for more than 30 days in the summer. The Jonda soils have a calcic horizon. The Judkins, Namon, Scandard, Tamred, and Timberlin soils have a lithic contact above 60 inches. The Mulgon soils have an albic horizon and soil temperatures greater than 40 degrees. Rocko soils have an ustic moisture regime. The Wapshilla soils have base saturation less than 60 percent in some subhorizon of the argillic.
GEOGRAPHIC SETTING: The Washboard soils formed in colluvium over till from andesite, rhyolite, breccia, or tuff on mountain slopes. Slopes range from 20 to 90 percent. Elevation ranges from 8,200 to 11,500 feet. The mean annual temperature is 31 to 42 degrees F. The mean annual precipitation is 25 to 35 inches. The frost-free period is 45 to 75 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Scout and Seitz soils. Scout soils are on backslopes and lack an argillic horizon. Seitz soils are on footslopes and backslopes and have more than 35 percent clay in the particle-size control section.
DRAINAGE AND PERMEABILITY: well drained; very high runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for wood products. Potential native vegetation is Engelmann spruce and subalpine fir with an understory of elk sedge, dwarf blueberry, common juniper, and kinnikinnick. It is in the Engelmann Spruce-Subalpine Fir Woodland Site, Forest Cover Type 206.
DISTRIBUTION AND EXTENT: Southwest Colorado in LRR E and MLRA 48A. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Ouray Soil Survey Area, Ouray County, Colorado, 1998. The name comes from Washboard Rock and Washboard Rock topographic quadrangle.
REMARKS: Diagnostic horizons and features recognized in this pedon.
Ochric epipedon: the zone from 1 to 13 inches (A1 and A2 horizons).
Argillic horizon: the zone from 24 to 66 inches (Bt1 and Bt2 horizon).
Particle-size control section - the upper 20 inches of the argillic horizon, the zone from 24 to 44 inches(Bt1 and part of Bt2 horizon).
This pedon was classified in accordance with Keys to Soil Taxonomy, 7th Edition, 1996. The superactive CEC activity class is presumed for this series based on the general trend indicated by lab data throughout this region.