LOCATION WOODGULCH MTEstablished Series
TAXONOMIC CLASS: Mixed, frigid Lamellic Ustipsamments
TYPICAL PEDON: Woodgulch stony loamy sand, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 1 inch; undecomposed and slightly decomposed forest litter.
A--1 to 5 inches; grayish brown (10YR 5/2) stony loamy sand, very dark grayish brown (10YR 3/2) moist; weak thin platy structure; slightly hard, very friable, slightly sticky and nonplastic; common fine and very fine roots; few medium and coarse roots; many clear sand grains; 5 percent surface stones, 5 percent pebbles, 5 percent cobbles; moderately acid (pH 5.8); clear smooth boundary. (2 to 5 inches thick)
E--5 to 14 inches; light brownish gray (10YR 6/2) loamy sand, dark grayish brown (10YR 4/2) moist; weak medium prismatic structure; slightly hard, very friable, slightly sticky and nonplastic; common fine and very fine roots; few medium and coarse roots; many very fine tubular and interstitial pores; many clear sand grains coating faces of peds; slightly acid (pH 6.5); gradual smooth boundary. (5 to 15 inches thick)
E/Bt--14 to 31 inches; E part (85 percent) pale brown (10YR 6/3) loamy sand, dark brown (10YR 4/3) moist; Bt part (15 percent) pale brown (10YR 6/3) sandy loam dark brown 10YR 3/3 moist; weak medium and fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few medium and coarse roots; many very fine tubular and interstitial pores; few faint clay films on faces of peds and bridging sand grains; many bleached sand grains on faces of peds; slightly acid (pH 6.1); gradual smooth boundary. (10 to 20 inches thick)
E and Bt--31 to 51 inches; E part (95 percent) pale brown (10YR 6/3) loamy sand, dark brown (10YR 4/3) moist; Bt part (5 percent) brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; weak medium and fine subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; few fine and very fine roots; many very fine tubular and interstitial pores; many clear sand grains; lamellae are 1/8 to 3/16 inch thick and total 1 inch thick; 5 percent pebbles; slightly acid (pH 6.2); gradual smooth boundary. (15 to 25 inches thick)
C--51 to 60 inches; light brownish gray (2.5Y 6/2) coarse sand, grayish brown (2.5Y 5/2) moist; single grain; loose; 10 percent angular pebbles; slightly acid (pH 6.5).
TYPE LOCATION: Lewis and Clark County, Montana; 1,700 feet east and 1,200 feet north of the SW corner of sec. 12, T. 9 N., R. 5 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 12 and 35 inches.
A horizon - Value: 4 or 5 dry, 3 moist
Chroma: 1 or 2
Clay content: 5 to 10 percent
Rock fragments: 5 to 35 percent--0 to 10 percent stones, 0 to 10 percent cobbles, 5 to 15 percent pebbles
Reaction: pH 5.6 to 6.5
E horizon - Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 or 3
Texture: sand or loamy sand
Clay content: 5 to 10 percent
Rock fragments: 0 to 5 percent pebbles
Reaction: pH 6.1 to 7.3
E/Bt horizon - Value: E part 6 or 7, Bt part 5 or 6 dry; E part 2 or 3, Bt part 3 or 4 moist
Chroma: 3 or 4
Clay content: 5 to 10 percent
Rock fragments: 0 to 5 percent pebbles
Reaction: pH 6.1 to 7.3
E and Bt horizon - Value: E part 6 or 7, Bt part 5 or 6 dry; E part 2 or 3, Bt part 3 or 4 moist
Chroma: 3 or 4
Lamellae: combined thickness of 1/4 to 3 inches
Clay content: 5 to 10 percent
Rock fragments: 0 to 5 percent
Reaction: pH 6.1 to 7.3
C horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 1 or 2
Texture: coarse sand or loamy sand
Clay content: 0 to 5 percent
Rock fragments: 5 to 30 percent pebbles
Reaction: pH 6.1 to 7.3
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - mountains.
Elevation - 4,500 to 5,500 feet.
Slope - 8 to 35 percent.
Parent material - material derived from coarse grained granite rock with a high content of mica.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual temperature - 40 to 45 degrees F.
Frost-free period - 90 to 110 days.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; rapid permeability.
USE AND VEGETATION: Woodgulch soils are used mainly for livestock grazing and for woodland. Potential native vegetation is mainly ponderosa pine and Douglas fir, with an understory of bluebunch wheatgrass, Idaho fescue, rough fescue, kinnikinnick, bitterbrush, mountain mahogany, pinegrass, white spirea, and western yarrow.
DISTRIBUTION AND EXTENT: Woodgulch soils are not extensive in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lewis and Clark County, Montana, 1991; proposed in Lewis and Clark County, Montana, 1979.
REMARKS: Soil interpretations record: MT0406, MT1147. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from 1 to 8 inches (mixed A and part of E horizons); an albic horizon from 5 to 14 inches (E horizon); a horizon of mixed albic and argillic materials from 14 to 31 inches (E/Bt horizon); a horizon with lamellae from 31 to 51 inches (E and Bt horizon); a particle-size control section from 10 to 40 inches below the mineral soil surface (E, E/Bt, E and Bt horizons). Woodgulch soils have a frigid temperature regime and an ustic moisture regime.
ADDITIONAL DATA: NSSL S89MT-049-001