LOCATION FIRETOWER MTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Cumulic Hapludolls
TYPICAL PEDON: Firetower loam, forested (colors are for dry soil unless otherwise noted).
A--0 to 6 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 4/3) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium roots; moderately acid (pH 6.0); clear wavy boundary. (6 to 10 inches thick)
Bw1--6 to 17 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, and medium roots; slightly acid (pH 6.2); gradual wavy boundary. (10 to 15 inches thick)
Bw2--17 to 29 inches; grayish brown (10YR 5/2) silt loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, and medium roots; slightly acid (pH 6.2); gradual wavy boundary. (10 to 15 inches thick)
Bw3--29 to 42 inches; light brownish gray (10YR 6/2) loam, grayish brown (10YR 5/2) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common fine and medium roots; few fine faint redox concentrations in root channels; slightly acid (pH 6.4); gradual wavy boundary. (10 to 15 inches thick)
C1--42 to 51 inches; light brownish gray (2.5Y 6/2) loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common medium roots; common fine distinct brownish yellow (10YR 6/6) redox concentrations; neutral (pH 6.6); gradual wavy boundary. (6 to 12 inches thick)
C2--51 to 60 inches; light gray (2.5Y 7/2) silt loam, grayish brown (2.5Y 5/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine distinct brownish yellow (10YR 6/6) redox concentrations; neutral (pH 6.6).
TYPE LOCATION: Lincoln County, Montana; 2,300 feet south and 2,100 feet east of the NW corner of sec. 23, T. 27 N., R. 28 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 8 and 24 inches.
Mollic epipedon thickness - 16 to 26 inches.
Depth to seasonal high water table - 24 to 42 inches.
A horizon - Value: 4 or 5 dry
Clay content: 5 to 18 percent
Reaction: pH 5.6 to 7.3
Bw1 horizon - Value: 4 or 5 dry
Clay content: 5 to 18 percent
Reaction: pH 5.6 to 7.3
Bw2 and Bw3 horizons - Value: 5 or 6 dry, 4 or 5 moist
Texture: silt loam or loam
Clay content: 5 to 18 percent
Reaction: pH 5.6 to 7.3
C1 and C2 horizons - Value: 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: loam or silt loam
Clay content: 5 to 18 percent
Reaction: pH 6.1 to 7.3
COMPETING SERIES:
Elkriver (MN) - has a lithologic discontinuity of sandy material at 25 to 44 inches.
GEOGRAPHIC SETTING:
Landform - low stream terraces.
Elevation - 3,300 to 3,800 feet.
Slope - 0 to 2 percent.
Parent material - alluvium.
Climate - long, cold winters; moist springs; warm, dry summers.
Mean annual precipitation - 24 to 30 inches, much of which falls as snow and spring rains.
Mean annual air temperature - 42 to 45 degreed F.
Frost-free period - 70 to 90 days.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained, moderate permeability.
USE AND VEGETATION: Firetower soils are used for woodland, understory grazing, and wildlife habitat. Potential native vegetation is mainly ponderosa pine, Douglas-fir, and western larch. Understory vegetation consists mainly of rough fescue, common snowberry, shrubby cinquefoil, forbs, and sedges.
DISTRIBUTION AND EXTENT: Firetower soils are of small extent in the valleys of northwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lincoln County, Montana, 1997.
REMARKS: Soil interpretation record: MT1363. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the surface to 17 inches (A1, A2 horizons); a cambic horizon from 17 to 42 inches (Bw1, Bw2 horizons); a particle-size control section from 10 to 40 inches (A2, Bw1, Bw2 horizons). Firetower soils have a frigid temperature regime and a udic moisture regime.
ADDITIONAL DATA: Laboratory data S92MT-053-008.