LOCATION EAGLEWING MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcic Haplustepts
TYPICAL PEDON: Eaglewing gravelly silt loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 1 inch; undecomposed needles and twigs.
E--1 to 12 inches; light brownish gray (10YR 6/2) gravelly silt loam, dark grayish brown (10YR 4/2) moist; moderate medium and coarse granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots and common medium roots; 20 percent gravel; neutral (pH 7.2); clear smooth boundary. (7 to 18 inches thick)
Bw--12 to 21 inches; pale brown (10YR 6/3) gravelly silt loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots and common medium roots; common fine pores; 25 percent gravel; neutral (pH 7.2); abrupt wavy boundary. (6 to 24 inches thick)
Bk1--21 to 28 inches; very pale brown (10YR 8/2) gravelly silt loam, light brownish gray (10YR 6/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots and few medium roots; common fine pores and few medium pores; 25 percent gravel; disseminated lime; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (0 to 10 inches thick)
Bk2--28 to 37 inches; very pale brown (10YR 8/2) gravelly silt loam, pale brown (10YR 6/3) moist; massive; soft, friable, slightly sticky and slightly plastic; common very fine and fine roots and few medium roots; few fine and medium pores; 20 percent hard gravel and 10 percent paragravel; disseminated lime; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (6 to 20 inches thick)
Bk3--37 to 60 inches; very pale brown (10YR 8/2) paragravelly silt loam, light gray (10YR 7/2) moist; massive; soft, friable, slightly sticky and slightly plastic; common very fine roots and few fine roots; 10 percent gravel and 15 percent paragravel; disseminated lime; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Lake County, Montana; 1,000 feet south and 1,700 feet west of the NE corner of sec. 8, T. 25 N., R. 20 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches; moist in all parts May through June; not dry for 45 consecutive days.
Depth to calcic horizon - 13 to 28 inches.
Some pedons have an E/Bw horizon 3 to 9 inches thick.
E horizon - Value: 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2 or 3
Texture: loam or silt loam
Clay content: 18 to 27 percent
Rock fragments: 5 to 35 percent--0 to 15 percent cobbles and stones, 5 to 25 percent gravel
Reaction: pH 6.6 to 7.3
Bw horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: silt loam or loam
Clay content: 18 to 27 percent
Rock fragments: 5 to 35 percent--0 to 10 percent cobbles and stones, 5 to 25 percent gravel
Reaction: pH 6.6 to 7.3
Bk1 horizon - Hue: 10YR or 2.5Y
Value: 7 or 8 dry; 5, 6, or 7 moist
Chroma: 2 or 3
Texture: silt loam or loam
Clay content: 18 to 27 percent
Rock fragments: 5 to 35 percent--0 to 10 percent cobbles and stones, 5 to 25 percent gravel
Calcium carbonate equivalent: 20 to 40 percent
Reaction: pH 7.9 to 8.4
Bk2 and Bk3 horizons - Hue: 10YR or 2.5Y
Value: 6, 7, or 8 dry; 5, 6, or 7 moist
Chroma: 2 or 3
Texture: silt loam or loam
Clay content: 15 to 27 percent
Rock fragments: 5 to 45 percent--0 to 15 percent cobbles and stones, 5 to 40 percent gravel (0 to 15 percent paragravel)
Calcium carbonate equivalent: 20 to 40 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
There are no competing series.
GEOGRAPHIC SETTING:
Landform- alluvial fans, hills, moraines and mountains.
Elevation - 2,800 to 5,200 feet.
Slope - 2 to 50 percent.
Parent material - loamy calcareous till or colluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 16 to 24 inches.
Mean annual air temperature - 38 to 45 degrees F.
Frost-free season - 70 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Eaglewing soils are used mainly as woodland. A few areas are used as pasture and for orchards. Potential native vegetation is mainly Douglas fir and ponderosa pine with an understory of pinegrass, common snowberry, mallow ninebark, kinnikinnick, and Oregongrape.
DISTRIBUTION AND EXTENT: Eaglewing soils are of small extent in northwestern Montana. MLRA 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lake County, Montana, 1991; proposed in Lake County, Montana, 1983. Eaglewing is a coined name.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the mineral soil surface to 7 inches (E horizon);
Cambic horizon - from 12 to 21 inches (Bw horizon);
Calcic horizon - from 21 to 60 inches (Bk1, Bk2, Bk3 horizons);
Particle-size control section - from 10 to 40 inches below the mineral soil surface (Bw, Bk1, Bk2, Bk3 horizons).
Eaglewing soils have a frigid temperature regime and an ustic moisture regime.
Soil interpretation records: MT0803.