LOCATION WETOPA COTentative Series
TAXONOMIC CLASS: Fine, smectitic Vertic Argicryolls
TYPICAL PEDON: Wetopa clay loam - Aspen woodland. (Colors are for dry soil unless otherwise noted.)
A--0 to 10 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; strong fine granular structure; soft, friable, slightly sticky and slightly plastic; slightly acid (pH 6.2); clear smooth boundary. (4 to 14 inches thick)
BA--10 to 18 inches; brown (7.5YR 4/2) clay loam, dark brown (7.5YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; 5 percent rock fragments; slightly acid (pH 6.4); clear smooth boundary. (8 to 17 inches thick)
Bt--18 to 34 inches; light reddish brown (5YR 6/4) clay, reddish brown (5YR 4/3) moist; strong medium angular blocky structure; hard, firm, sticky and plastic; 10 percent rock fragments; moderately acid (pH 6.0); clear wavy boundary. (10 to 29 inches thick)
BC--34 to 60 inches; light reddish brown (5YR 6/4) clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; moderately acid (pH 6.0).
TYPE LOCATION: Gunnison County, Colorado; 1,500 feet west and 300 feet north of the east quarter corner of Sec. 17, T. 11 S., R. 90 W. Latitude 39 degrees 6 minutes, 0 seconds N; longitude 107 degrees, 27 minutes, 31 seconds west.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 38 to 40 degrees F. These soils are usually moist when the soil temperature is above 41 degrees F. Reaction is moderately acid to neutral.
Depth to the base of the argillic horizon ranges from 22 to 50 inches. Rock fragments range from 0 to 25 percent in the A and Bt horizons, and from 0 to 35 percent below the Bt horizon.
The A horizon has hue of 10YR through 5YR, value of 4 or 5, 2 or 3 moist, and chroma of 2 or 3. Reaction is moderately acid to neutral.
The Bt horizon has hue of 7.5YR or 5YR, value of 5 or 6, 4 or 5 moist, and chroma of 2 through 4. Textures are clay loam, or clay with clay ranging from 35 to 55 percent. Reaction is moderately acid or slightly acid.
The BC or C horizon, if present, has hue of 7.5YR or 5YR, value of 5 or 6, 4 or 5 moist, and chroma of 3 or 4. The lower subhorizons and substratum are clay. Reaction ranges from moderately acid or slightly acid.
COMPETING SERIES: These are the Cratermo (ID), Hammersley (OR), and Telefono (NM) soils. The Cratermo and Telefono series have a lithic contact at 20 to 40 inches. The Hamersley soils have a highly weathered paralithic contact at 50 inches.
GEOGRAPHIC SETTING: Wetopa soils are on valley side slopes. Slopes range from 0 to 65 percent. The soils formed in residuum derived from interbedded sandstone and shale with surface basalt in some areas. The mean annual temperature ranges from 38 to 44 degrees F., and the mean annual precipitation ranges from 30 to 40 inches. Elevation ranges from 7,500 to 10,000 feet. Frost-free period is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hayrack and Tellura soils. Hayrack soils have an eluviated horizon. Tellura soils have greater than 35 percent rock fragments in the particle size control section.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: This soil is an Aspen woodland site with an understory of snowberry, wheatgrasses, fescues, bromes, and other forbs and grasses. It is used for summer livestock grazing, firewood, pulpwood, and recreation.
DISTRIBUTION AND EXTENT: West central Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Gunnison County (Grand Mesa-West Elk Soil Survey Area), Colorado, 1986.
REMARKS: This soil was originally called Cochetopa, moist. The name was coined from "wet Cochetopa". This soil was sampled by the NSSL in 1985, Sample No. S85-08-051- 002, NSSL ID No. LSP8504. Diagnostic features include a mollic epipedon from 0 to 18 inches and an argillic layer from 18 to 34 inches. Last updated by the state 2/92.