LOCATION HOFLY COEstablished Series
TAXONOMIC CLASS: Fine, smectitic Pachic Haplocryolls
TYPICAL PEDON: Hofly loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; dark gray (10YR 4/1) loam, very dark grayish brown (2.5Y 3/2) moist; weak thin platy structure parting to moderate very fine granular; slightly hard, friable, slightly sticky and slightly plastic; neutral (pH 7.2); clear smooth boundary. (3 to 8 inches thick)
Bw--3 to 32 inches; dark gray (10YR 4/1) clay loam, very dark grayish brown (2.5Y 3/2) moist; moderate fine subangular blocky structure; hard, firm, slightly sticky and moderately plastic; neutral (pH 7.2); abrupt smooth boundary. (13 to 35 inches thick)
C--32 to 60 inches; olive brown (2.5Y 4/4) clay, dark grayish brown (2.5Y 4/2) moist; massive; very hard, very firm, slightly sticky and moderately plastic; 5 percent cobbles; neutral (pH 7.2).
TYPE LOCATION: San Miguel County, Colorado; about 10 miles north of Placerville, Colorado; located about 800 feet north and 250 feet east of the southwest corner of sec. 16, T. 45 N., R. 10 W.; Horsefly Peak USGS quad; lat. 38 degrees 08 minutes 50 seconds N. and long. 107 degrees 38 minutes 58 seconds W., NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture regime: ustic
Mean annual soil temperature: 37 to 41 degrees F.
Mean summer soil temperature: 47 to 56 degrees F.
Thickness of the mollic epipedon: 16 to 35 inches
Particle size control section:
Clay content: 35 to 45 percent
Coarse fragment content: averages 0 to 5 percent
A horizon:
Hue: 10YR or 2.5Y
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 1 or 2, dry or moist
Bw horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 or 2, dry or moist
Texture: clay loam, clay
C horizon:
Hue: 10YR or 2.5Y,
Value: 4 to 6 dry, 4 or 5 moist
Chroma: 2 to 4, dry or moist
Texture: clay loam, clay
COMPETING SERIES: There are currently no other series in this family. Hoosan soils in a closely related family have mixed mineralogy.
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium derived dominantly from shale, with some influence from residuum.
Landform: mountain slopes, hills, and mesas.
Slopes: 5 to 40 percent.
Elevation: 8,500 to 10,000 feet.
Mean annual air temperature: 35 to 40 degrees F.
Mean annual precipitation: 20 to 26 inches.
Wettest months: July and August.
Driest Months: May and June receive slightly less precipitation than other months however, the soils are still moist from snowmelt.
Frost-free period: 40 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Adel, Baird Hollow, Nordicol, and Ryman soils. Adel soils are fine-loamy. Baird Hollow and Nordicol soils are skeletal and have an argillic horizon. Ryman soils have mixed mineralogy.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; slow permeability.
USE AND VEGETATION: These soils are used for summer livestock grazing and wildlife habitat. Principal native vegetation is Gambel's oak, mountain snowberry, mountain brome, elk sedge, Arizona fescue, western wheatgrass, and mountain muhly. Brushy Loam range site.
DISTRIBUTION AND EXTENT: Southwestern Colorado. MLRA 48A. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: San Miguel County (San Miguel Area), Colorado, 1987.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon (pachic feature): from 0 to 32 inches (A and Bw horizons).
Particle-size control section: the zone from 10 to 40 inches (part of the Bw and part of the C horizons).
The 02/1997 revision changed clay mineralogy from mixed to smectitic.
Keys to Soil Taxonomy: Series classified according to Eighth Edition, 1998