LOCATION CROWFOOT COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Alfic Argiustolls
TYPICAL PEDON: Crowfoot coarse sandy loam - forest. (Colors are for dry soil unless otherwise noted.)
A1--0 to 11 inches; dark grayish brown (10YR 4/2) coarse sandy loam, very dark brown (10YR 2/2) moist; moderate very fine granular structure; soft, very friable; slightly acid; gradual wavy boundary. (7 to 15 inches thick)
A2--11 to 16 inches; light gray (10YR 7/2) loamy coarse sand, grayish brown (10YR 5/2) moist; weak thin platy structure that parts to single grains; soft, loose; vesicular; 5 percent fine and very fine angular granitic gravel; neutral; gradual wavy boundary. (4 to 10 inches thick)
A&B--16 to 22 inches; mixed light gray (10YR 7/2) and grayish brown (10YR 5/2) loamy coarse sand containing nodules of coarse sandy clay loam, grayish brown (10YR 5/2) and dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; hard, very friable; peds are very hard, very friable; thin clay films on some peds and in root channels and pores in the more clayey parts of the horizon; 5 percent fine and very fine angular gravel; neutral; gradual wavy boundary. (4 to 10 inches thick)
B2t--22 to 40 inches; grayish brown (10YR 5/2) coarse sandy clay loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, very friable, slightly sticky, slightly plastic; peds are extremely hard, very friable; continuous clay films on peds and in root channels and pores; 5 percent fine and very fine angular granite gravel; neutral; gradual wavy boundary. (11 to 20 inches thick)
B3--40 to 48 inches; light brownish gray (10YR 6/2) coarse sandy loam, grayish brown (10YR 5/2) moist; weak medium subangular blocky structure; very hard, very friable; thin clay films on some peds and in root channels and pores; 10 percent fine and very angular granite gravel; neutral; gradual wavy boundary. (4 to 10 inches thick)
C--48 to 60 inches; light gray (2.5Y 7/1) coarse sandy loam, gray (2.5Y 6/1) moist; massive; extremely hard, very friable; 10 percent fine and very fine angular granite gravel; neutral.
TYPE LOCATION: Douglas County, Colorado; 1,320 feet west and 85 feet north of the E 1/4 corner of Sec. 28, T. 10 S., R. 66 W.
RANGE IN CHARACTERISTICS: Crowfoot soils are noncalcareous to depths of more than 40 inches, and are noncalcareous in at least the upper 3 inches of the C horizon if the solum exceeds 40 inches. Base saturation in all subhorizons of the argillic horizon usually exceeds 80 percent and ranges from 60 to 100 percent. Rock fragments range from 0 to 15 percent by volume in a major part of the solum and in the C horizon and are mainly less than 3 inches in diameter but range from 1/8 to 10 inches in diameter. The solum and C horizon range from slightly acid through mildly alkaline. The mean annual soil temperature is 45 degrees F, and the mean summer soil temperature is 62 degrees F.
The A1 horizon has hue of 2.5Y through 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 through 3.
The A2 horizon has hue of 2.5Y through 7.5YR, value of 5 through 8 dry, 4 through 7 moist, and chroma of 1 through 4.
The B2t horizon usually has hue of 2.5Y through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 1 through 6. Subhorizons redder than 7.5YR occur in some pedons. This horizon is typically coarse sandy clay loam and has 18 to 35 percent clay, 5 to 35 percent silt, and 40 to 75 percent sand with more than 35 percent being fine or coarser sand and with a large proportion of the sand fraction being medium, coarse, and very coarse angular granite sand.
The C horizon has hue of 2.5Y through 7.5YR. Subhorizons redder than 7.5YR occur in some pedons. This horizon is typically coarse sandy loam and has less than 18 percent clay.
COMPETING SERIES: These are the Kelvin, Redtom, Tomah, and Westcreek series. Kelvin soils are calcareous in the lower part of the solum and in the C horizon and have continuous horizons of secondary calcium carbonate accumulation. Redtom soils have hue of 5YR or redder, soils have B2t horizons in which silicate clay is accumulating in discontinuous lamellae. Westcreek soils have more than 15 percent rock fragments in a major part of the control section.
GEOGRAPHIC SETTING: Crowfoot soils are on alluvial fans, valley side slopes, and upland hills and ridges. Slope gradients range from 2 to 15 or more percent. The soils formed in parent sediments weathered residually or locally transported from the arkosic beds of the Dawson and Arapahoe formations. In some locations the parent sedimentary rock occurs above 60 inches but is of such low contrast that it cannot be consistently identified. The average annual precipitation is 17 inches, with peak periods of precipitation occurring in the spring and early summer.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pring soils and the competing Tomah soils. Pring soils lack A2 or A&B horizons and are moderately coarse textured.
DRAINAGE AND PERMEABILITY: Well drained; medium to slow runoff; moderate permeability.
USE AND VEGETATION: These soils are used for forestry, native pastureland, and for recreation. Principal native vegetation is mainly Gambel oak, big bluestem, little bluestem, sandreed grass, and widely spaced ponderosa pine.
DISTRIBUTION AND EXTENT: The foothills and Black Forest areas of east- central Colorado. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Douglas County, Colorado, 1974.
REMARKS: Last updated by the state 8/74.