LOCATION MITTEN MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Andic Eutrudepts
TYPICAL PEDON: Mitten gravelly ashy silt loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches; undecomposed and slightly decomposed forest litter.
Bw--2 to 11 inches; light yellowish brown (10YR 6/4) gravelly ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, medium, and coarse roots; 15 percent angular gravel; slightly acid (pH 6.4); abrupt wavy boundary. (7 to 12 inches thick)
2E--11 to 18 inches; pinkish gray (7.5YR 7/2) very gravelly sandy loam, brown (7.5YR 5/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, medium, and coarse roots; 45 percent angular gravel, 5 percent angular cobbles; slightly acid (pH 6.2); clear wavy boundary. (4 to 25 inches thick)
2E and Bw--18 to 36 inches; E part (80 percent) is pinkish gray (7.5YR 7/2) extremely gravelly sandy loam, brown (7.5YR 5/2) moist; B part (20 percent) is brown (7.5YR 5/4) extremely gravelly sandy loam, lamellae, brown (7.5YR 4/4) moist; the lamellae are 1/4 to 1/2 inch thick; massive; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium, and coarse roots; 50 percent angular gravel, 15 percent angular cobbles; slightly acid (pH 6.2); diffuse irregular boundary. (8 to 35 inches thick)
2BC--36 to 60 inches; pinkish gray (7.5YR 7/2) extremely gravelly sandy loam, brown (7.5YR 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium, and coarse roots; 50 percent angular gravel, 15 percent angular cobbles; neutral (pH 6.6).
TYPE LOCATION: Missoula County, Montana; 1,500 feet east of the NW corner of sec. 13, T. 12 N., R. 19 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 46 degrees F.
Moisture control section - between 8 and 24 inches.
Volcanic ash and loess mantle - 7 to 14 inches thick (bulk density of less than 1.0 grams per cubic centimeter); Al + 1/2 Fe greater than or equal to 1 percent.
Bw horizon
Value: 4 or 5 moist
Chroma: 3 or 4
Clay content: 5 to 12 percent
Rock fragments: 15 to 50 percent--0 to 30 percent angular cobbles; 10 to 45 percent angular gravel
Moist bulk density: 1.0 g/cc or less
Al + 1/2 Fe: 1 percent or more
Reaction: pH 5.6 to 6.5
2E horizon
Hue: 10YR or 7.5YR
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: very fine sandy loam, fine sandy loam, sandy loam, and loam
Clay content: 5 to 12 percent
Rock fragments: 35 to 80 percent--5 to 10 percent angular cobbles; 30 to 70 percent angular gravel
Reaction: pH 5.6 to 6.5
2E and Bw horizon
Hue: E part 7.5YR or 10YR; B part 2.5Y, 7.5YR or 10YR
Value: E part 6 or 7, B part 5 or 6 dry; E part 4, 5 or 6, B part 4 or 5 moist
Chroma: E part 2 or 3; B part 3 or 4
Texture: very fine sandy loam, fine sandy loam, sandy loam, or loam
Clay content, mixed: 5 to 12 percent
Rock fragments: 50 to 80 percent--0 to 5 percent stones; 10 to 20 percent angular cobbles; 40 to 60 percent angular gravel
Reaction: pH 5.6 to 6.5
Some pedons have a 2Bw and E horizon below the 2E and Bw horizon.
2BC horizon
Hue: 10YR or 7.5YR
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2 or 3
Texture: fine sandy loam, sandy loam, coarse sandy loam, and loam
Clay content: 5 to 12 percent
Rock fragments: 60 to 85 percent--0 to 5 percent stones; 10 to 20 percent angular cobbles; 45 to 65 percent angular gravel
Reaction: pH 5.6 to 7.3
COMPETING SERIES:
Bendahl (MT) - has horizons of secondary carbonate accumulation.
Courville (MT) - does not contain lamellae.
GEOGRAPHIC SETTING:
Landform- mountain slopes and escarpments.
Elevation - 2,200 to 6,000 feet.
Slope - 8 to 70 percent.
Parent material - volcanic ash over colluvium derived from argillite and quartzite.
Climate - long, cold winters; moist springs; warm summers. Mean annual precipitation - 22 to 45 inches.
Mean annual temperature - 38 to 44 degrees F.
Frost-free period - 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderately rapid permeability.
USE AND VEGETATION: Mitten soils are used mainly for timber production, wildlife habitat, and for watersheds. Potential native vegetation is coniferous forest consisting of western larch, Douglas fir, grand fir, ponderosa pine, and lodgepole pine with an understory of twinflower, blue huckleberry, dwarf huckleberry, common beargrass, oceanspray and pinegrass.
DISTRIBUTION AND EXTENT: Mitten soils are of moderate extent in western Montana. MLRA 43A and 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Missoula County, Montana, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 7 inches (Oi and Bw horizons);
Cambic horizon - 18 to 36 inches (2E and Bw horizon);
Albic horizon - 11 to 18 inches (2E horizon);
Particle-size control section - 10 to 40 inches (Bw, 2E, 2E and Bw, and 2BC horizons).
Mitten soils have a frigid temperature regime and a udic moisture regime.
ADDITIONAL DATA: Soil interpretation records MT0404, MT8051 and MT8106.