LOCATION CORRALGULCH             CO

Established Series
Rev. CRP/JCK
04/2019

CORRALGULCH SERIES

The Corralgulch series consists of very deep, well drained soils that formed in colluvium or slope alluvium derived from igneous and metamorphic rock. These soils are on mountain slopes, structural benches and escarpments. Slopes are 8 to 65 percent. Mean annual precipitation is about 356 mm, and mean annual air temperature is about 8.5 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Argiustolls

TYPICAL PEDON: Corralgulch gravelly loam, at an elevation of 2,195 meters. (Colors are for dry soil unless otherwise noted.)

A--0 to 20 cm; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine and very fine, common medium and few coarse roots; 15 percent gravel and 2 percent cobbles; slightly alkaline (pH 7.6); clear wavy boundary. (18 to 30 cm thick)

Bt1--20 to 30 cm; brown (10YR 4/3) gravelly sandy clay loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; many fine and very fine, common medium and few coarse roots; 15 percent faint clay films on faces of peds; 15 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.6); clear wavy boundary.

Bt2--30 to 51 cm; brown (10YR 5/3) gravelly sandy clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure parting to moderate fine subangular blocky; hard, friable, moderately sticky and moderately plastic; many fine and very fine, common medium and few coarse roots; few fine dendritic tubular pores; 60 percent distinct clay films on faces of peds; 15 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.4); clear wavy boundary. (combined thickness of Bt horizons is 25 to 40 cm)

Btk--51 to 94 cm; brown (10YR 5/3) gravelly sandy clay loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; common fine and very fine and few medium roots; few fine dendritic tubular pores; 20 percent distinct clay films on faces of peds; 10 percent fine, medium and coarse threadlike carbonate masses in the matrix; 20 percent gravel and 5 percent cobbles; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (15 to 50 cm thick)

Bk1--94 to 130 cm; grayish brown (10YR 5/2) sandy clay loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine roots; 15 percent fine, medium and coarse threadlike and irregular shaped carbonate masses in the matrix; 3 percent gravel and 1 percent cobbles; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (30 to 48 cm thick)

Bk2--130 to 154 cm; brown (10YR 5/3) loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine roots; 10 percent fine and medium threadlike and irregular shaped carbonate masses in the matrix; 5 percent gravel and 1 percent cobbles; strongly effervescent; moderately alkaline (pH 8.0).

TYPE LOCATION: 1.2 kilometers South and 305 meters East of the northwest corner of section 6 T 48N, R 6W; USGS Cimarron Topographic Quadrangle; 38 degrees, 26 minutes, 36.3 seconds north latitude and 107 degrees, 34 minutes, 29.6 seconds west longitude. NAD27

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 8 to 11 degrees C
Mollic epipedon thickness - 18 to 40 cm
Depth to argillic base - 58 to 120 cm
Particle-size control section (weighted average):
Clay content - 20 to 35 percent
Rock fragment content - 15 to 35 percent

A horizons
Hue: 7.5 YR or 10YR
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: loam or sandy loam
Clay content: 12 to 20 percent
Rock fragments: 15 to 35 percent - 15 to 35 percent gravel, 0 to 10 percent cobbles
Reaction: pH 7.0 to 7.8

Bt horizons
Hue: 7.5 YR or 10YR
Value: 4, 5 or 6 dry; 2, 3 or 4 moist
Chroma: 2, 3 or 4 dry or moist
Texture: sandy clay loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 15 to 35 percent - 15 to 35 percent gravel, 0 to 10 percent cobbles
Reaction: pH 7.2 to 7.8

Btk horizon
Hue: 7.5 YR or 10YR
Value: 5, 6, or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4 dry or moist
Texture: sandy clay loam, clay loam or loam
Clay content: 18 to 35 percent
Rock fragments: 5 to 35 percent - 5 to 35 percent gravel, 0 to 10 percent cobbles
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 8.0 to 8.4

Bk horizons
Hue: 7.5 YR or 10YR
Value: 5, 6, or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4 dry or moist
Texture: loam, sandy clay loam or clay loam
Clay content: 18 to 35 percent
Rock fragments: 5 to 35 percent - 5 to 35 percent gravel, 0 to 10 percent cobbles
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 8.0 to 8.4

COMPETING SERIES:
Ascalon (CO) - have less than 15 percent rock fragments in the particle-size control section
Belfon (KS) - have a calcic horizon; have lithologic discontinuities
Bresser (CO) - do not have an accumulation of secondary calcium carbonate
Cedak (WY) - are moderately deep to a paralithic contact
Charkiln (NV) - do not have an accumulation of secondary calcium carbonate
Critchell (CO) - do not have an accumulation of secondary calcium carbonate
Dagflat (UT) - are moderately deep to a lithic contact; do not have an accumulation of secondary calcium carbonate
Datil (NM) - have a calcic horizon
Featherlegs (WY) - have a calcic horizon; have a lithologic discontinuity
Forgan (OK) - have a lithologic discontinuity
Hargreave (WY) - are moderately deep to a paralithic contact; do not have an accumulation of secondary calcium carbonate
Harlan (WY) - have hue redder than 7.5YR
Hemingford (NE) - are deep to a paralithic contact; do not have an accumulation of secondary calcium carbonate
Hiarc (NM) - are moderately deep to a lithic contact; do not have an accumulation of secondary calcium carbonate
Kirtley (WY) - are moderately deep to a paralithic contact; do not have an accumulation of secondary calcium carbonate
Lavate (UT) - do not have an accumulation of secondary calcium carbonate
Loarc (NM) - do not have an accumulation of secondary calcium carbonate
Moskee (WY) - have less than 15 percent rock fragments in the particle-size control section
Noden (WY) - do not have an accumulation of secondary calcium carbonate
Palmer Canyon (WY) - have a lithologic discontinuity; have more than 35 percent rock fragments in the lower part of the subsoil
Recluse (WY) - have less than 15 percent rock fragments in the particle-size control section
Satanta (KS) - have a lithologic discontinuities; have a mean annual soil temperature greater than 11 degrees C
Shalona (CO) - have less than 15 percent rock fragments in the particle-size control section
Sitcan (CO) - have less than 15 percent rock fragments in the particle-size control section
Sugardee (WY) - have less than 15 percent rock fragments in the particle-size control section; have hue redder than 7.5YR
Wages (CO) - have an argillic base with a depth less than 58 cm
Wolf (WY) - have a calcic horizon

GEOGRAPHIC SETTING:
Landform - mountain slopes, structural benches and escarpments
Elevation - 1,829 to 2,286 meters
Slope - 8 to 65 percent
Parent material - colluvium or slope alluvium
Mean annual precipitation - 305 to 406 mm
Mean annual air temperature - 7.2 to 10 degrees C
Frost-free period - 105 to 155 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bendire and Signalhill soils. Bendire and Signalhill soils are on similar landscape positions but have more than 35 percent rock fragments in the particle size control section.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: Corralgulch soils are used for rangeland, wildlife habitat and recreation. Native vegetation is mainly Wyoming big sagebrush, western wheatgrass, muttongrass, squirreltail and prairie Junegrass.

DISTRIBUTION AND EXTENT: Corralgulch soils are of small extent in southwestern Colorado. MLRA 36 and 48A.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Montrose County, Colorado - Ridgway Area, Colorado, Parts of Delta, Gunnison, Montrose, and Ouray Counties, 2019.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 30 cm (A and Bt1 horizons)
Argillic horizon - from 20 to 94 cm (Bt1, Bt2 and Btk horizons)
Secondary calcium carbonate accumulation - from 51 to 154 cm (Btk, Bk1 and Bk2 horizons)
Particle-size control section - from 20 to 70 cm (Bt1, Bt2 and part of Btk horizon)

Corralgulch soils have a mesic temperature regime and an ustic moisture regime bordering on aridic.

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National Cooperative Soil Survey
U.S.A.