LOCATION REDCHIEF                MT

Established Series
Rev. JB-JJU-RJS
06/2011

REDCHIEF SERIES

The Redchief series consists of very deep, well drained soils that formed in till, glaciofuvial deposits, slope alluvium or colluvium. These soils are on till plains, outwash plains, hills, and mountains. Slopes are 0 to 60 percent. Mean annual precipitation is about 18 inches, and mean annual air temperature is about 39 degrees F.

TAXONOMIC CLASS: Clayey-skeletal, smectitic Ustic Argicryolls

TYPICAL PEDON: Redchief gravelly loam, rangeland (colors are for dry soil unless otherwise noted).

A--0 to 10 inches; very dark grayish brown (10YR 3/2) gravelly loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, and common medium roots; many very fine and fine interstitial pores; 20 percent gravel and 5 percent cobbles; moderately acid (pH 5.6); clear wavy boundary. (10 to 16 inches thick)

Bt1--10 to 18 inches; yellowish brown (10YR 5/4) very gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; hard, friable, slightly sticky and moderately plastic; common very fine and fine, and few medium and coarse roots; many very fine, fine and medium interstitial pores; many faint clay films of faces of peds; 35 percent gravel and 15 percent cobbles; slightly acid (pH 6.1); clear wavy boundary. (5 to 10 inches thick)

Bt2--18 to 28 inches; light yellowish brown (10YR 6/4) very gravelly clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and fine interstitial pores; many faint clay films on faces of peds; 35 percent gravel and 20 percent cobbles; neutral (pH 6.6); gradual wavy boundary. (4 to 12 inches thick)

Bt3--28 to 60 inches; pale brown (10YR 6/3) extremely gravelly clay loam; dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; few very fine and fine interstitial pores; many faint clay films on faces of peds; 45 percent gravel and 20 percent cobbles; neutral (pH 6.6).

TYPE LOCATION: Powell County, Montana; 1,900 feet north and 50 feet west of the southeast corner of sec. 3, T. 10N, R. 6W.

RANGE IN CHARACTERISTICS:
Soil temperature - 36 to 45 degrees F.
Mollic epipedon thickness - 10 to 16 inches
Depth to base of argillic horizon - greater than 50 inches

A horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 2 to 5 dry; 2 or 3 moist
Chroma: 1 to 3; dry or moist
Texture: loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 15 to 40 percent--5 to 35 percent gravel, 0 to 25 percent cobbles, stones and boulders
Reaction: pH 5.1 to 7.3

Bt1 horizon
Hue: 5YR, 7.5YR or 10YR; dry or moist
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 to 8; dry or moist
Texture: clay loam or clay
Clay content: 35 to 60 percent
Rock fragments: 25 to 60 percent--15 to 50 percent gravel, 0 to 20 percent cobbles and stones
Reaction: pH 5.1 to 7.3

Bt2 horizon
Hue: 5YR, 7.5YR or 10YR; dry or moist
Value: 4 to 6 dry; 4 or 5 moist
Chroma: 4 to 8; dry or moist
Clay content: 35 to 60 percent
Rock fragments: 35 to 70 percent--30 to 50 percent gravel, 5 to 30 percent cobbles and stones
Reaction: pH 5.1 to 7.3

Bt3 horizon
Hue: 2.5YR, 5YR, 7.5YR or 10YR; dry or moist
Value: 4 to 6 dry; 4 or 5 moist
Chroma: 2 to 8; dry or moist
Clay content: 35 to 60 percent
Rock fragments: 35 to 70 percent--30 to 60 percent gravel, 5 to 20 percent cobbles and stones
Reaction: pH 5.1 to 7.3

COMPETING SERIES:
Embargo (CO) - are moderately deep to a lithic contact
Evna (CO) - have 5 to 30 percent boulders in the Range In Characteristics for the Bt horizons
Passar (CO) - have rock fragments mainly larger than 10 inches in diameter
Rooset (WY) - have secondary calcium carbonate accumulation
Tellura (CO) - the base of the argillic horizon is at a depth of less than 50 inches

GEOGRAPHIC SETTING:
Landform - till plains, outwash plains, hills and mountains
Elevation - 4,800 to 8,600 feet
Slope - 0 to 60 percent
Parent material - till, glaciofluvial deposits, slope alluvium or colluvium
Climate - long, cold winters; cool, moist springs; warm summers
Mean annual precipitation - 15 to 24 inches
Mean annual air temperature - 34 to 43 degrees F.
Frost-free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Copenhaver and Mollet series. Copenhaver soils are loamy-skeletal and shallow to a lithic contact. They are on hills. Mollet soils are fine textured and on alluvial fans.

DRAINAGE AND PERMEABILITY: Well drained; slow permeability.

USE AND VEGETATION: Redchief soils are used for rangeland except for a few fields of introduced grasses for hay and pasture. Potential native vegetation is mainly rough fescue, Idaho fescue, bluebunch wheatgrass, Columbia needlegrass, forbs, and shrubs. Scattered lodgepole pine, aspen, and alpine fir are present in higher elevation areas.

DISTRIBUTION AND EXTENT: Redchief soils are of moderate extent in central and western Montana. MLRAs - 43B, 44B, 46.

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

SERIES ESTABLISHED: Glacier County (Blackfeet Reservation), Montana, 1969. Type location moved to Powell County, Montana, 1993.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 10 inches (A horizon)
Argillic horizon - from 10 to greater than 60 inches (Bt1, Bt2, Bt3 horizons)
Particle-size control section from 10 to 30 inches (Bt1, Bt2, part of Bt3 horizons)

Redchief soils have a cryic temperature regime and an ustic moisture regime.

ADDITIONAL DATA: Soil interpretations records - MT0453, MT8192, MT8077, MT8193, MT9030.

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National Cooperative Soil Survey
U.S.A.