LOCATION OWLCREEK COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Haplocryalfs
TYPICAL PEDON: Owlcreek loam, on a northeast facing 37 percent mountain slope under a spruce-fir woodland at an elevation of 9,340 feet. (colors are for dry soil unless otherwise noted. When described on September 3, 1987, the soil was moist below 10 inches.)
E--0 to 6 inches; pale brown (10YR 6/3) loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; slightly acid (pH 6.4); clear smooth boundary. (5 to 20 inches thick)
BE--6 to 10 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; 5 percent gravel; neutral (pH 6.8); gradual smooth boundary. (0 to 10 inches thick)
Bt1--10 to 24 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; strong coarse angular blocky structure; hard, firm, sticky and plastic; many distinct clay films on faces of peds; 10 percent gravel; neutral (pH 6.8); gradual smooth boundary.
Bt2--24 to 38 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; strong very coarse angular blocky structure; hard, firm, sticky and plastic; many distinct clay films on faces of peds; 5 percent gravel; neutral (pH 6.8); gradual smooth boundary. (combined thickness of the Bt horizons is 20 to 40 inches)
BC--38 to 66 inches; light brownish gray (10YR 6/2) cobbly clay loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; 5 percent gravel, 10 percent cobbles; neutral (pH 7.0). (18 to 36 inches thick)
TYPE LOCATION: Gunnison County, Colorado; about 16 miles south of Cimarron, Colorado; within an unsectionized area of Uncompahgre National Forest, estimated to be in Section 28, T. 46 N., R. 6 W.; USGS Courthouse Mountain topographic quadrangle; latitude 38 degrees, 12 minutes, 42 seconds north and longitude 107 degrees, 32 minutes, 21 seconds west, NAD 1927.
RANGE IN CHARACTERISTICS:
Soil moisture regime: udic
Mean annual soil temperature: 36 to 45 degrees F.
Thickness of ochric epipedon: 5 to 20 inches.
Depth to top of argillic horizon: 8 to 23 inches.
Particle-size control section:
Clay content: 28 to 34 percent clay
Rock fragment content: 0 to 25 percent
E and BE horizons:
Hue: 7.5YR or 10YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 or 3 dry or moist
Texture: L, GR-L
Rock fragments: andesite, rhyolite, breccia, or tuff. 0 to 15 percent total rock fragments; 0 to 15 percent gravel.
Reaction: slightly acid (pH 6.1) to neutral (pH 7.3)
Bt horizons:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 3 or 4 dry or moist
Texture: CL, GR-CL
Rock fragments: andesite, rhyolite, breccia, or tuff. 0 to 20 percent total rock fragments; 0 to 20 percent gravel, 0 to 5 percent cobbles.
BC horizon:
Hue: 7.5YR or 10YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 or 3 dry or moist
Texture: CB-CL, CL
Rock fragments: andesite, rhyolite, breccia, or tuff. 0 to 25 percent total rock fragments; 0 to 10 percent gravel, 0 to 20 percent cobbles.
COMPETING SERIES: These are the Ansel and Jaegie series. In addition the following series may be competitors when reclassified: the Castelleia, Edloe, Ericson, Graysill (T), Grimstone, Haviland (T), Hierro, Indart, Limber, Perceton, Sapphire, Schofield, Shule, Swifton, Tongue River, Trapper, Whitefish, and Woodrock. series.
Ansel soils are dry for 30 or more days during the summer.
Castelleia and
Limber soils have argillic horizons less than 14 inches thick.
Edloe,
Graysill,
Grimstone, Limber,
Sapphire,
Schofield,
Shule,
Trapper, and
Woodrock soils have a lithic contact within 60 inches.
Ericson soils have annual soil temperature higher than 45 degrees F.
Haviland soils have sandstone and shale rock fragments.
Haviland and
Hierro soils have hue redder than 7.5YR in the argillic horizon and below.
Jaegie soils have combination (E/Bt) horizons.
Indart,
Perceton, and
Tongue River soils have a paralithic contact within 40 inches.
Swifton soils have a glossic horizon and the upper boundary of the argillic is deeper than 24 inches.
Whitefish soils have horizons of secondary carbonate accumulations.
GEOGRAPHIC SETTING: The Owlcreek soils formed in slope alluvium and colluvium from andesite, rhyolite, breccia, or tuff on mountain slopes and ridges. Slopes range from 5 to 40 percent. Elevation ranges from 9,000 to 11,400 feet. The mean annual temperature is about 31 to 40 degrees F. The mean annual precipitation is about 26 to 35 inches. The frost-free period is 45 to 65 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Needleton and Scout family soils. Needleton soils are on backslopes and shoulders and have more than 35 percent rock fragments in the particle-size control section. Scout family soils are on backslopes and have more than 35 percent rock fragments in the particle-size control section.
DRAINAGE AND PERMEABILITY: well drained; high to very high runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for timber 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: Western 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, Uncompahgre National Forest, Gunnison County, Colorado, 1998. The name comes from Owl Creek in this area.
REMARKS: Diagnostic horizons and features recognized in this pedon are:.
Albic horizon: the zone from 0 to 6 inches (E horizon).
Ochric epipedon: the zone from 0 to 10 inches. (E and BE horizons)
Argillic horizon: the zone from 10 to 38 inches. (Bt1 and Bt2 horizons)
Particle-size control section: the upper 20 inches of the argillic horizon, from 10 to 30 inches (Bt1 and part of the 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.