LOCATION BENDAHL MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Andic Eutrudepts
TYPICAL PEDON: Bendahl gravelly ashy silt loam, forested (colors are for moist soil unless otherwise noted).
Oi--0 to 1 inch; undecomposed and slightly decomposed forest litter. (1 to 2 inches thick)
A--1 to 2 inches; brown (10YR 4/3) gravelly ashy silt loam, brown (10YR 5/3) dry; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and medium and few coarse roots; 20 percent gravel; moderately acid (pH 6.0); abrupt wavy boundary. (1 to 3 inches thick)
Bw--2 to 8 inches; dark yellowish brown (10YR 4/4) gravelly ashy silt loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure parting to moderate fine and medium granular; soft, very friable, nonsticky and nonplastic; many fine and medium and few coarse roots; 20 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (6 to 9 inches thick)
2E--8 to 18 inches; pale brown (10YR 6/3) very gravelly loam, light gray (10YR 7/2) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and common medium roots; 5 percent cobbles and 35 percent gravel; neutral (pH 6.8); gradual wavy boundary. (6 to 11 inches thick)
2E/Bw--18 to 28 inches; E part (60 percent) is pale brown (10YR 6/3) very gravelly loam, light gray (10YR 7/2) dry; B part (40 percent) is yellowish brown (10YR 5/4) very gravelly loam, pale brown (10YR 6/3) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and common medium roots; 5 percent cobbles and 40 percent gravel; slightly alkaline (ph 7.6); gradual wavy boundary. (9 to 11 inches thick)
2Bk1--28 to 39 inches; light brownish gray (10YR 6/2) very gravelly loam, very pale brown (10YR 8/2) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium and few coarse roots; 10 percent cobbles and 35 percent gravel; disseminated lime, common distinct lime coatings on undersides of rock fragments; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (11 to 15 inches thick)
2Bk2--39 to 60 inches; light brownish gray (10YR 6/2) very cobbly loam, very pale brown (10YR 8/2) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; 20 percent cobbles and 35 percent gravel; disseminated lime, many distinct lime coatings on undersides of rock fragments; violently effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Sanders County, Montana; 2300 feet west and 2300 feet north of the southheast corner of section 12, T.25N., R.27W.
RANGE IN CHARACTERISTICS:
Soil Temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
A horizon - Value: 5 or 6 dry, 3 or 4 moist
Clay content: 5 to 15 percent
Rock fragments: 15 to 20 percent gravel
Moist bulk density: 0.85 to 1.00 g/cc
Acid oxalate extractable Al + 1/2 Fe: 1 to 2 percent
Reaction: pH 5.6 to 6.5
Bw horizon - Value: 5 or 6 dry, 4 or 5 moist
Clay content: 5 to 15 percent
Rock fragments: 15 to 20 percent gravel
Moist bulk density: 0.85 to 1.00 g/cc
Acid oxalate extractable Al + 1/2 Fe: 1 to 2 percent
Reaction: pH 5.6 to 6.5
2E horizon - Value: 7 or 8 dry, 5 or 6 moist
Chroma: 2 or 3
Clay content: 10 to 27 percent
Rock fragments: 35 to 45 percent--0 to 5 percent cobbles, 35 to 40 percent gravel
Reaction: pH 6.1 to 7.3
2E/Bw horizon - Hue: 10YR or 2.5Y
Value: E part 7 or 8 dry, 5 or 6 moist; B part 6 or 7 dry, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: loam or sandy loam
Clay content: 10 to 27 percent
Rock fragments: 40 to 55 percent--5 to 10 percent cobbles, 35 to 45 percent gravel
Reaction: pH 6.1 to 7.8
2Bk1 horizon - Hue: 10YR or 2.5Y
Value: 7 or 8 dry, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: loam or sandy loam
Clay content: 10 to 27 percent
Rock fragments: 40 to 55 percent--10 to 15 percent cobbles, 25 to 40 percent gravel
Calcium carbonate equivalent: 15 to 35 percent
Reaction: pH 7.9 to 8.4
2Bk2 horizon - Hue: 10YR or 2.5Y
Value: 7 or 8 dry, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: loam or sandy loam
Clay content: 10 to 27 percent
Rock fragments: 50 to 65 percent--15 to 30 percent cobbles, 25 to 35 percent gravel
Calcium carbonate equivalent: 15 to 35 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Courville (MT) - does not have horizons of secondary carbonate accumulation.
Mitten (MT) - does not have horizons of secondary carbonate accumulation.
GEOGRAPHIC SETTING:
Landform- moraines and mountains.
Elevation - 3,600 to 4,500 feet.
Slope - 15 to 50 percent.
Parent material - volcanic ash over calcareous glacial till or colluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 26 to 34 inches.
Mean annual temperature - 40 to 45 degrees F.
Frost free period - 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Bendahl soils are used mainly for timber production, understory grazing, and wildlife habitat. Potential native vegetation is mainly Douglas fir, western larch, ponderosa pine, lodgepole pine, and grand fir. Understory vegetation is twinflower, queencup beadlilly, dwarf huckleberry, snowberry, and pinegrass.
DISTRIBUTION AND EXTENT: Bendahl soils are of small extent in northwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Sanders County, Montana 19975.
REMARKS: Soil Interpretation Record: MT1618. Diagnostic horizons and features recognized in this pedon are: ash influenced layers from 1 to 8 inches (A, Bw horizons); an ochric epipedon from the mineral soil surface to 8 inches (A, Bw horizons); an albic horizon from 8 to 18 inches (2E horizon); calcic horizons from 29 to 60 inches (2Bk1, 2Bk2 horizons); a particle-size control section from 10 to 40 inches below the mineral soil surface 2E, 2E/Bw, 2Bk1, and 2Bk2 horizons). Bendahl soils have a frigid temperature regime and a udic moisture regime.