LOCATION BENDOH MTEstablished Series
TAXONOMIC CLASS: Ashy, glassy Ustivitrandic Haplocryepts
TYPICAL PEDON: Bendoh very gravelly loam, in forest (colors are for dry soil unless otherwise noted).
Oi--0 to 1 inch; partially decomposed needles, twigs and leaves.
A--1 to 3 inches; dark grayish brown (10YR 4/2) very gravelly ashy loam, very dark grayish brown (10YR 3/2) moist, weak medium granular structure; slightly hard, very friable, slightly sticky and nonplastic; 5 percent cobbles and 35 percent gravel; strongly acid (pH 5.2); clear smooth boundary. (0 to 4 inches thick)
E--3 to 7 inches; grayish brown (10YR 5/2) gravelly ashy loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine and fine pores; 5 percent cobbles and 15 percent gravel; moderately acid (ph 5.8); clear wavy boundary. (2 to 8 inches thick)
Bw--7 to 15 inches; light brownish gray (10YR 6/2) gravelly ashy sandy clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots, few medium roots; many very fine and fine pores; 5 percent cobbles and 15 percent gravel; moderately acid (pH 6.0); gradual wavy boundary.
BC--15 to 29 inches; light gray (2.5Y 7/2) gravelly ashy sandy clay loam, olive gray (5Y 4/2) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine pores; 10 percent cobbles and 20 percent gravel; moderately acid (pH 6.0); gradual irregular boundary. (Combined thickness of B horizons is 16 to 40 inches thick)
C1--29 to 43 inches; light gray (2.5Y 7/2) gravelly ashy sandy clay loam, olive gray (5Y 5/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine and fine pores; 10 percent cobbles and 25 percent gravel; slightly acid (pH 6.2); gradual irregular boundary.
C2--43 to 51 inches; light gray (5Y 7/2) very gravelly ashy sandy clay loam, olive gray (5Y 5/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; 15 percent cobbles and 40 percent gravel; slightly acid (pH 6.4); gradual wavy boundary.
Cr--51 to 56 inches; light gray (5Y 7/2) decomposing welded tuff bedrock that crushes to gravelly or very gravelly ashy sandy clay loam; slightly acid (pH 6.4). (4 to 8 inches thick)
R--56 inches; light gray (5Y 7/2) fractured welded tuff bedrock.
TYPE LOCATION: Deer Lodge County, Montana; 2000 feet south and 2400 feet west of the NE corner of section 16, T. 3 N., R. 11 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 32 to 40 degrees F.
Mean summer soil temperature - 40 to 46 degrees F.
Moisture control section - between 4 and 12 inches.
Volcanic glass - 30 to 50 percent in the coarse silt and sand fraction.
Acid oxalate Al + 1/2 Fe - .12 to .20 percent.
Depth to Cr horizon 40 to 55 inches.
Base saturation - more than 60 percent in one or more horizons between 10 and 30 inches.
Depth to bedrock: 55 to 60 inches.
A horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 3, 4 or 5 moist
Chroma: 2 or 3
Clay content: 18 to 27 percent
Rock fragments: 15 to 45 percent--0 to 10 percent cobbles and stones, 15 to 35 percent gravel
Reaction: pH 5.1 to 6.5
E horizon - Hue: 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2 or 3
Texture: ashy loam, ashy sandy loam or ashy sandy clay loam
Clay content: 15 to 27 percent
Rock fragments: 15 to 35 percent--0 to 15 percent cobbles and stones, 15 to 30 percent gravel
Reaction: pH 5.1 to 6.5
Bw horizon - Hue: 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 1, 2 or 3
Texture: ashy loam, ashy sandy loam or ashy sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 5 to 35 percent--0 to 10 percent cobbles and stones, 5 to 30 percent gravel
Reaction: pH 5.6 to 7.3
BC and C1 horizons - Hue: 2.5Y or 5Y
Value: 6 or 7 dry; 4, 5 or 6 moist
Chroma: 1 or 2
Texture: ashy loam, ashy sandy loam or ashy sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 15 to 35 percent--0 to 10 percent cobbles and stones, 15 to 30 percent gravel
Reaction: pH 5.6 to 7.3
C2 horizon - Hue: 2.5Y or 5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 1 or 2
Texture: ashy sandy loam, ashy loam, or ashy sandy clay loam
Clay content: 15 to 25 percent
Rock fragments: 15 to 60 percent--0 to 15 percent cobbles and stones, 15 to 40 percent gravel
Reaction: pH 5.6 to 7.3
COMPETING SERIES:
Daras (MT) - does not have a paralithic contact above 60 inches.
Eremis (MT) - does not have a paralithic contact above 60 inches.
GEOGRAPHIC SETTING:
Landform- mountains.
Elevation - 5,000 to 8,000 feet.
Slope - 2 to 70 percent.
Parent material - colluvium and alluvium over welded tuff or rhyolite bedrock.
Climate - long, cold winters; cool, moist springs; short, cool summers
Mean annual precipitation - 20 to 30 inches.
Mean annual air temperature - 30 to 38 degrees F.
Frost-free period - 30 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Bendoh soils are mainly used for woodland, wildlife and watershed. The potential native vegetation is mainly subalpine fir, lodgepole pine, Douglas-fir (at lower elevations), whitebark pine (at higher elevations), grouse whortleberry, white spiraea, pinegrass, blue huckleberry, elk sedge, common beargrass and common snowberry.
DISTRIBUTION AND EXTENT: Bendoh soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Deer Lodge County, Montana, 1999.
REMARKS: Soil interpretation record: MT1748. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the mineral surface to 7 inches (A and E horizons); a cambic horizon from 7 to 29 inches (Bw and BC horizons); a particle size control section from 10 to 40 inches (Bw, BC and C1 horizons); a layer of decomposed welded tuff from 51 to 56 inches (Cr horizon); welded tuff bedrock at 56 inches (R horizon). Bendoh soils have a cryic temperature regime and an ustic moisture regime bordering on udic.
The 3/2008 description reflects a change in classification from Ashy, glassy Vitrandic Eutrocryepts to Ashy, glassy Ustivitrandic Haplocryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.