LOCATION HUGHESVILLE MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, frigid Calcic Hapludolls
TYPICAL PEDON: Hughesville flaggy loam, woodland (colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches; forest litter of undecomposed and decomposed needles, twigs, and cones. (0 to 3 inches thick)
A--2 to 4 inches; dark grayish brown (10YR 4/2) flaggy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine, medium, and coarse roots; 15 percent flagstones, 10 percent channers; slightly alkaline (pH 7.8); clear wavy boundary. (1 to 3 inches thick)
Bw--4 to 12 inches; brown (10YR 4/3) very flaggy clay loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many fine, medium, and coarse roots; many fine and medium irregular pores; 30 percent flagstones, 15 percent channers; few distinct lime casts on undersides of coarse fragments; slightly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (6 to 10 inches thick)
Bk1--12 to 24 inches; pale brown (10YR 6/3) very flaggy loam, dark brown (10YR 4/3) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine, medium, and coarse roots; many fine and medium irregular pores; 35 percent flagstones, 15 percent channers; common distinct lime cast on undersides of coarse fragments; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (6 to 14 inches thick)
Bk2--24 to 34 inches; light gray (10YR 7/2) extremely flaggy loam, pale brown (10YR 6/3) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine, medium, and coarse roots; many fine and medium irregular pores; 30 percent flagstones; 10 percent stones; 30 percent channers; common distinct lime casts on undersides of coarse fragments; violently effervescent; disseminated lime; moderately alkaline (pH 8.4); clear wavy boundary. (6 to 10 inches thick)
Bk3--34 to 40 inches; very pale brown (10YR 8/2) extremely flaggy loam, very pale brown (10YR 7/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots and few medium roots; many fine and medium pores; 50 percent flagstones, 15 percent stones, 25 percent channers; common distinct lime casts on undersides of coarse fragments; violently effervescent; disseminated lime; moderately alkaline (pH 8.4).
R--40 inches; fractured hard limestone.
TYPE LOCATION: Fergus County, Montana; 250 feet north and 405 feet west of the SE corner of sec. 36, T. 13 N., R. 18 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 44 degrees F.
Moisture control section - between 4 and 12 inches; moist in some or all parts throughout the year in 6 or more out of 10 years.
Mollic epipedon thickness - 7 to 13 inches.
Depth to bedrock - 20 to 40 inches.
Depth to calcic horizon - 7 to 13 inches.
A horizon - Hue: 7.5YR to 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Texture: loam, clay loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 20 to 35 percent--0 to 5 percent stones; 10 to 15 percent angular cobbles; 10 to 15 percent angular pebbles.
Reaction: pH 6.6 to 7.8
Bw horizon - Hue: 2.5YR to 2.5Y
Value: 4 or 5 dry; 3 moist
Chroma: 2 or 3
Texture: loam, clay loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 35 to 60 percent--0 to 5 percent stones; 25 to 35 percent cobbles; 10 to 20 percent pebbles
Calcium Carbonate Equivalent: 0 to 5 percent
Reaction: pH 7.4 to 8.4
Bk1 horizon - Hue: 7.5YR to 5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3
Texture: loam, clay loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 35 to 60 percent--0 to 5 percent stones; 25 to 35 percent cobbles; 10 to 20 percent pebbles
Calcium Carbonate Equivalent: 40 to 50 percent
Reaction: pH 7.4 to 8.4
Bk2 and Bk3 horizons - Hue: 10YR to 5Y
Value: 7 or 8 dry; 6 or 7 moist
Chroma: 2 or 3
Texture: loam, clay loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 60 to 90 percent--0 to 10 percent stones; 35 to 40 percent cobbles; 25 to 40 percent pebbles
Calcium Carbonate Equivalent: 50 to 60 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - mountains and hills.
Elevation - 4,000 to 6,000 feet.
Slope - 2 to 60 percent.
Parent material - residuum or colluvium derived mainly from limestone.
Climate - long, cold winters; moist springs; warm, moist summers.
Mean annual precipitation - 19 to 24 inches.
Mean annual temperature - 39 to 43 degrees F.
Frost-free period - 75 to 110 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability
USE AND VEGETATION: Hughesville soils are used mainly for forest products and rangeland. Potential native vegetation is mainly Douglas-fir and ponderosa pine with an understory of white spiraea, mallow ninebark, kinnikinnick, russet buffaloberry, pinegrass, common juniper, rough fescue, Idaho fescue, bluebunch wheatgrass, arrowleaf balsamroot, western meadowrue, Oregon-grape, and heartleaf arnica.
DISTRIBUTION AND EXTENT: Hughesville soils are of moderate extent in the mountains of central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Judith Basin County, Montana, 1963.
REMARKS: Soil Interpretations Record: MT0342. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from 2 to 12 inches (A and Bw horizon); a calcic horizon from 12 to 40 inches (Bk1, Bk2 and Bk3 horizons); a lithic contact at 40 inches (R horizon); a particle-size control section from 12 to 40 inches (Bk1, Bk2 and Bk3 horizons). Hughesville soils have a frigid temperature regime and a udic moisture regime.