LOCATION BEAVERDUMP MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Vitrandic Hapludalfs
TYPICAL PEDON: Beaverdump gravelly ashy 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 4 inches; dark yellowish brown (10YR 4/4) gravelly ashy loam, yellowish brown (10YR 5/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, fine and medium and common coarse roots; 15 percent pebbles; slightly acid (pH 6.2); clear wavy boundary. (0 to 3 inches thick)
Bw--4 to 11 inches; yellowish brown (10YR 5/4) gravelly ashy loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine, fine and medium and common coarse roots; 20 percent pebbles; moderately acid (pH 5.8); clear wavy boundary. (6 to 11 inches thick)
2E/Bt--11 to 28 inches; E part (60 percent) is brown (10YR 5/3) very gravelly sandy loam, pale brown (10YR 6/3) dry, Bt part (40 percent) is dark yellowish brown (10YR 4/4) very gravelly sandy loam, yellowish brown (10YR 5/4) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, medium and coarse roots; common distinct clay films on faces of peds; 5 percent cobbles, 40 percent pebbles; neutral (pH 6.6); gradual irregular boundary. (8 to 20 inches thick)
2Bt/E--28 to 51 inches; Bt part (60 percent) is dark yellowish brown (10YR 4/4) very cobbly sandy loam, yellowish brown (10YR 5/4) dry, E part (40 percent) is brown (10YR 5/3) very cobbly sandy loam, pale brown (10YR 6/3) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, medium and coarse roots; common distinct clay films on faces of peds; 25 percent cobbles, 35 percent pebbles; slightly acid (pH 6.4); gradual irregular boundary. (12 to 26 inches thick)
2C--51 to 60 inches; pale brown (10YR 6/3) extremely cobbly loamy coarse sand, very pale brown (10YR 7/3) dry; single grain; loose, nonsticky and nonplastic; few fine and medium roots; 35 percent cobbles, 35 percent pebbles; moderately acid (pH 5.6).
TYPE LOCATION: Sanders County, Montana; 800 feet east and 1,800 feet south of the northwest corner of sec. 8, T. 23N., R. 30W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 8 and 24 inches.
A horizon - Value: 5 or 6 dry, 4 or 5 moist
Clay content: 8 to 15 percent
Bulk density: 1.0 to 1.4 g/cc
Volcanic glass: 5 to 20 percent
Acid oxalate extractable Al + 1/2 Fe: 0.4 to 1.0 percent
Rock fragments: 15 to 25 percent; 0 to 5 percent cobbles, 15 to 20 percent pebbles
Reaction: 5.6 to 6.5
Bw horizon - Value: 5 or 6 dry, 4 or 5 moist
Clay content: 8 to 15 percent
Bulk density: 1.0 to 1.4 g/cc
Volcanic glass: 5 to 20 percent
Acid oxalate extractable Al + 1/2 Fe: 0.4 to 1.0 percent
Rock fragments: 15 to 25 percent; 0 to 5 percent cobbles, 15 to 20 percent pebbles
Reaction: 5.6 to 6.5
2E/Bt horizon - Value: E part 6 or 7 dry, 5 or 6 moist
B part 5 or 6 dry, 4 or 5 moist
Clay content: 10 to 20 percent
Rock fragments: 40 to 60 percent; 5 to 15 percent cobbles, 35 to 45 percent pebbles
Reaction: 5.6 to 7.3
2Bt/E horizon - Value: B part 5 or 6 dry, 4 or 5 moist
E part 6 or 7 dry, 5 or 6 moist
Clay content: 10 to 20 percent
Rock fragments: 40 to 60 percent; 15 to 25 percent cobbles, 25 to 35 percent pebbles
Reaction: 5.6 to 7.3
2C horizon - Value: 5, 6, or 7 dry, 4, 5, or 6 moist
Clay content: 5 to 15 percent
Rock fragments: 60 to 90 percent; 25 to 35 percent cobbles, 35 to 55 percent pebbles
Reaction: 5.6 to 6.5
COMPETING SERIES:
There are no competing series.
GEOGRAPHIC SETTING:
Landform - stream terraces.
Elevation - 2,200 to 2,800 feet.
Slope - 0 to 35 percent.
Parent material - mixed alluvium and glacial outwash.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 24 to 28 inches.
Mean annual temperature - 42 to 45 degrees F.
Frost-free period - 90 to 105 days.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained, moderately rapid permeability.
USE AND VEGETATION: Beaverdump soils are used mainly for woodland, understory grazing, and wildlife habitat. Potential native vegetation is mainly ponderosa pine, Douglas fir, western larch, and grand fir. Understory vegetation is mainly pinegrass, oceanspray, common snowberry, bracken fern, starry false Solomons seal, elk sedge, and other forbs, shrubs, and grasses.
DISTRIBUTION AND EXTENT: Beaverdump soils are of small extent in the valleys of northwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Sanders County, Montana, 1997.
REMARKS: Soil Interpretation Record: MT1378. Diagnostic horizons and features recognized in this pedon are: an ash influenced layer from 1 to 11 inches (A, Bw horizon); an ochric epipedon from the mineral soil surface to 8 inches mixed (A, Bw horizons); an argillic horizon from 28 to 51 inches (2Bt/E horizon); a particle size control section from 28 to 48 inches (2Bt/E horizon). Beaverdump soils have a frigid temperature regime and a udic moisture regime.