LOCATION MUSSELSHELL MT
Established Series
Rev. JB-GFB-EMM
04/2014
MUSSELSHELL SERIES
The Musselshell series consists of very deep, well drained soils that formed in alluvium or colluvium. These soils are on alluvial fans, fan remnants, stream terraces, escarpments and hills. Slopes are 0 to 60 percent. Mean annual precipitation is about 12 inches, and mean annual temperature is about 42 degrees F.
TAXONOMIC CLASS: Coarse-loamy, carbonatic, frigid Aridic Calciustepts
TYPICAL PEDON: Musselshell loam, rangeland (colors are for dry soil unless otherwise noted).
A--0 to 3 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (2 to 4 inches thick)
Bk1--3 to 13 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine roots and pores; few fine threads of lime; violently effervescent; moderately alkaline (pH 8.3); gradual wavy boundary.
Bk2--13 to 29 inches; very pale brown (10YR 7/3) loam, pale brown (10YR 6/3) moist; massive; hard, firm, slightly sticky and slightly plastic; common very fine roots; many very fine pores; 5 percent limestone gravel with pendants of lime; few threads of lime; violently effervescent; moderately alkaline (pH 8.3); abrupt wavy boundary. (Combined thickness of Bk horizons is 22 to 36 inches)
2C--29 to 60 inches; pale brown (10YR 6/3) very gravelly fine sandy loam, brown (10YR 5/3) moist; massive; few very fine roots; 50 percent gravel; violently effervescent; moderately alkaline (pH 8.3).
TYPE LOCATION: Wheatland County, Montana; 600 feet south and 100 feet west of the center of sec. 24, T. 9 N., R. 16 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 47 degrees F.
Moisture control section - 8 to 24 inches, dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is higher than 41 degrees F.
Depth to 2C horizon - 20 to 40 inches.
A horizon
Hue: 10YR or 2.5Y
Value: 4, 5, or 6 dry; 3 or 4 moist
Chroma: 2, 3 or 4, dry or moist
Texture: loam or silt loam
Clay content: 10 to 27 percent
Rock fragments: 0 to 60 percent; 0 to 10 percent stones, 0 to 25 percent cobbles, 0 to 35 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.4 to 8.4
Bk horizons
Hue: 10YR or 2.5Y
Value: 5, 6, 7 or 8 dry; 4, 5, 6 or 7 moist
Chroma: 1, 2, 3 or 4, dry or moist
Texture: loam or sandy loam
Clay content: 10 to 27 percent
Rock fragments: 0 to 35 percent; 0 to 10 percent cobbles, 0 to 25 percent gravel
Calcium carbonate equivalent: 40 to 60 percent
Reaction: pH 7.9 to 9.0
2C horizon
Hue: 10YR or 2.5Y
Value: 5, 6, 7, or 8 dry; 4, 5, 6 or 7 moist
Chroma: 2, 3, or 4, dry or moist
Texture: fine sandy loam, sandy loam or loam Clay content: 10 to 18 percent
Rock fragments: 35 to 60 percent; 5 to 10 percent cobbles, 30 to 50 percent gravel
Calcium carbonate equivalent: 40 to 60 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - alluvial fans, fan remnants, stream terraces, escarpments and hills
Elevation - 2,700 to 6,500 feet
Slope - 0 to 60 percent
Parent material - alluvium or colluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 10 to 14 inches
Mean annual air temperature - 38 to 45 degrees F.
Frost-free period - 70 to 135 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Musselshell soils are used mainly for rangeland; some areas are dry farmed to wheat or irrigated to hay and pasture. Potential native vegetation is mainly western wheatgrass, needleandthread, blue grama, and threadleaf sedge.
DISTRIBUTION AND EXTENT: Musselshell soils are extensive in central and western Montana. MLRAs 43B, 44B, 46, and 58A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Upper Musselshell Valley Area, Montana, 1941.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the soil surface to 3 inches mixed (A horizon)
Calcic horizon - from 3 to 60 inches (Bk1, Bk2 and 2C horizons)
Particle-size control section - from 10 to 40 inches (Bk1, Bk2 and 2C horizons)
Soil Interpretations Records: MT0442, MT8131, Mt1378, MT9045.
Musselshell soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
Lincoln Laboratory S70MT-107-2; S70MT-107-3, S65MT-049-001.
National Cooperative Soil Survey
U.S.A.