LOCATION COYOTEFLATS             MT

Established Series
REV. KTS-RJS-EMM
07/2012

COYOTEFLATS SERIES

The Coyoteflats series consists of very deep, well drained soils that formed in alluvium or colluvium derived from mixed sources. These soils occur on fan remnants, stream terraces, escarpments and hills. Slopes are 0 to 35 percent. Mean annual precipitation is about 330 mm, and the mean annual temperature is about 5 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcidic Haplustalfs

TYPICAL PEDON: Coyoteflats loam, in rangeland on a 2 percent slope at an elevation of 1865 meters (Colors are for dry soil unless otherwise noted).

A--0 to 10 cm; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak medium and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots throughout; many very fine and fine irregular pores throughout; 10 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (8 to 15 cm thick)

Bt1--10 to 23 cm; brown (10YR 5/3) gravelly loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine and fine roots throughout; many very fine and fine dendritic tubular pores; many distinct discontinuous clay films on faces of peds; 15 percent gravel; neutral (pH 6.8); clear wavy boundary. (13 to 41 cm thick)

Bt2--23 to 36 cm; brown (10YR 5/3) very gravelly loam, brown (10YR 4/3) moist; moderate fine and medium fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots throughout; many very fine and fine dendritic tubular pores; common distinct patchy clay films on faces of peds; 35 percent gravel, 5 percent cobbles; neutral (pH 7.0); clear wavy boundary. (0 to 25 cm thick)

Bk1--36 to 51 cm; pale brown (10YR 6/3) very cobbly sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots throughout; common very fine and fine irregular pores throughout; 25 percent gravel, 25 percent cobbles; disseminated calcium carbonate and few fine patchy soft masses and threads of calcium carbonate throughout; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary.

Bk2--51 to 107 cm; very pale brown (10YR 7/3) extremely gravelly sandy loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots throughout; common very fine and fine irregular pores throughout; 45 percent gravel, 25 percent cobbles; disseminated calcium carbonate and many fine and medium patchy soft masses and threads of calcium carbonate throughout; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (Combined thickness of Bk horizons - 25 to 91 cm)

C--107 to 152 cm; light yellowish brown (10YR 6/4) extremely cobbly sand, pale brown (10YR 6/3) moist; single grain; loose, nonsticky and nonplastic; 40 percent gravel, 40 percent cobbles; disseminated calcium carbonate; slightly effervescent; slightly alkaline (pH 7.8).

TYPE LOCATION: Beaverhead County, Montana; Mill Point topographic quadrangle. UTM 12T, 340176e., 5011996n. NAD 83; 2200 feet south and 1950 feet east of the NE corner of sec. 11, T. 7 S., R 12 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C.
Depth to calcic horizon - 25 to 61 cm
Depth to top of argillic horizon - 8 to 13 cm
Particle-size control section - averages less than 35 percent rock fragments

A horizon
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3; dry or moist
Texture: loam or sandy loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 30 percent--0 to 20 percent gravel, 0 to 15 percent cobbles
Reaction: pH 6.1 to 7.3

Bt1 horizon
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4; dry or moist
Texture: loam, clay loam or sandy clay loam
Clay content: 18 to 35 percent
Rock fragments: 10 to 35 percent--5 to 20 percent gravel, 0 to 10 percent cobbles
Reaction: pH 6.6 to 7.6

Bt2 horizon
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: loam, clay loam or sandy clay loam
Clay content: 18 to 35 percent
Rock fragments: 10 to 45 percent--5 to 40 percent gravel, 0 to 20 percent cobbles
Reaction: pH 6.6 to 7.6

Btk horizon present in some pedons.

Bk horizons
Value: 6 to 8 dry; 5 or 6 moist
Chroma: 2 to 4; dry or moist
Texture: loam, sandy clay loam or sandy loam
Clay content: 10 to 27 percent
Rock fragments: 30 to 75 percent--25 to 50 percent gravel, 5 to 30 percent cobbles
Calcium carbonate equivalent: 5 to 35 percent
Reaction: pH 7.9 to 8.4
Note: Calcium carbonate equivalent is greater than 15 percent when the clay content is greater than 18 percent.

C horizon
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2 to 4; dry or moist
Texture: sand, loamy sand or sandy loam
Clay content: 0 to 15 percent
Rock fragments: 30 to 80 percent--25 to 50 percent gravel, 5 to 45 percent cobbles
Calcium carbonate equivalent: 0 to 4 percent
Reaction: pH 6.6 to 7.8

COMPETING SERIES:
Mantlemine (CO) - have hues redder then 10YR
Potrio (CO) - have a lithic contact at depths of less than 102 cm

GEOGRAPHIC SETTING:
Landform - fan remnants, stream terraces, escarpments and hills
Elevation - 1450 to 2075 meters
Slope - 0 to 35 percent
Parent material - mixed alluvium or colluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 250 to 360 mm
Mean annual air temperature - 4 to 7 degrees C.
Frost-free period - 70 to 100 days

GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Dyce, Bronec, Geohrock and Varney soils. The Dyce soils are moderately deep, fine textured soils and occur on adjacent hills. The Bronec and Geohrock soils are loamy-skeletal and the Varney soil is fine-loamy; all are very deep alluvial soils and occur on similar landforms.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: Coyoteflats soils are used mainly for rangeland and wildlife habitat. Potential native vegetation is mainly mountain and Wyoming big sagebrush, rabbitbrush, bluebunch wheatgrass, Poa (species), and miscellaneous forbs and half-shrubs.

DISTRIBUTION AND EXTENT: Coyoteflats soils are of small extent in southwestern Montana. MLRAs - 43B, 44B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Horse Prairie-South Valley Area - Part of Beaverhead County, Montana, 2011; proposed in Beaverhead County, Montana, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the soil surface to 10 cm (A horizon)
Argillic horizon - from 10 to 36 cm (Bt horizons)
Calcic horizon - from 36 to 107 cm (Bk1 and Bk2 horizons)
Particle-size control section - from 10 to 36 cm (Bt horizons)

Coyoteflats soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.

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National Cooperative Soil Survey
U.S.A.