LOCATION IFFGULCH MTEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, frigid Typic Endoaquolls
TYPICAL PEDON: Iffgulch clay, forested (colors are for moist soil unless otherwise noted).
A--0 to 2 inches; very dark grayish brown (10YR 3/2) clay, dark grayish brown (10YR 4/2) dry; strong fine and medium granular structure; hard, firm, sticky and plastic; many very fine, fine, and medium roots; moderately acid (pH 6.0); clear wavy boundary. (1 to 4 inches thick)
Bg1--2 to 10 inches; very dark gray (10YR 3/1) clay, gray (10YR 5/1) dry; moderate medium prismatic structure parting to strong medium subangular blocky; hard, firm, sticky and plastic; many very fine, fine, and medium roots; slightly acid (pH 6.2); clear wavy boundary. (4 to 12 inches thick)
Bg2--10 to 24 inches; gray (5Y 5/1) silty clay, gray (5Y 6/1) dry; moderate medium prismatic structure parting to strong medium subangular blocky; very hard, very firm, sticky and plastic; common very fine, fine, and medium roots; few fine prominent yellowish brown (10YR 5/6) redox concentrations; neutral (pH 6.8); clear wavy boundary. (10 to 18 inches thick)
Bg3--24 to 33 inches; gray (5Y 6/1) silty clay, light gray (5Y 7/1) dry; moderate medium prismatic structure parting to strong medium subangular blocky; very hard, very firm, sticky and plastic; common very fine, fine, and medium roots; few fine prominent yellowish brown (10YR 5/6) redox concentrations; neutral (pH 6.8); clear wavy boundary. (6 to 12 inches thick)
Cg1--33 to 46 inches; gray (5Y 6/1) clay loam, light gray (5Y 7/1) dry; massive; very hard, very firm, sticky and plastic; few fine and medium roots; common fine and medium prominent yellowish brown (10YR 5/6) redox concentrations, many fine and medium distinct greenish gray (5G 6/1) redox depletions; neutral (pH 7.0); gradual wavy boundary. (10 to 16 inches thick)
Cg2--46 to 60 inches; gray (5Y 6/1) gravelly clay loam, light gray (5Y 7/1) dry; massive; very hard, very firm, sticky and plastic; few fine and medium roots; common fine and medium prominent yellowish brown (10YR 5/6) redox concentrations, many fine and medium distinct greenish gray (5G 6/1) redox depletions; 15 percent pebbles, 5 percent cobbles; neutral (pH 7.0).
TYPE LOCATION: Sanders County, Montana; 2100 feet west and 1500 feet south of the northeast corner of section 36, T. 25 N., R. 32 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 4 and 12 inches
Mollic epipedon thickness - 7 to 16 inches
Depth to seasonal water table - 12 to 24 inches
A horizon - Value: 3, 4, or 5 dry; 2 or 3 moist
Clay content: 40 to 60 percent
Reaction: 5.6 to 6.5
Bg1 horizon - Value: 4 or 5 dry, 2 or 3 moist
Clay content: 40 to 60 percent
Reaction: 5.6 to 6.5
Bg2 and Bg3 horizons - Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Clay content: 40 to 60 percent
Reaction: 5.6 to 7.3
Cg1 horizon - Hue: 5Y, 5GY, or 5G
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Clay content: 27 to 40 percent
Reaction: 5.6 to 7.3
Cg2 horizon - Hue: 5Y, 5GY, or 5G
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Clay content: 27 to 40 percent
Coarse fragments: 15 to 35 percent--0 to 5 percent cobbles, 15 to 30 percent pebbles
Reaction: 5.6 to 7.3
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - swales and ephemeral drainages which disect stream terraces in glaciolacustrine landforms.
Elevation - 2200 to 2800 feet.
Slope- 0 to 4 percent.
Parent material - alluvium from glaciolacustrine deposits.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 28 to 34 inches.
Mean annual temperature - 42 to 45 degrees F.
Frost-free period - 90 to 105 days.
DRAINAGE AND PERMEABILITY: Poorly drained; slow permeability.
USE AND VEGETATION: Iffgulch soils are used mainly for woodland, understory grazing, and wildlife habitat. Potential native vegetation is mainly quaking aspen, black cottonwood, lodgepole pine, and Douglas fir. Understory vegetation is mainly black hawthorn, Douglas spirea, thinleaf alder, common snowberry, potentilla species, carex species, equisetum species, cow parsnip, false hellebore, coolwort foamflower, ladyfern, western swordfern, and other forbs, shrubs, and grasses.
DISTRIBUTION AND EXTENT: Iffgulch 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: MT1514. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 10 inches (A, Bg1 horizons); gleyed horizons with redox features (Bg2, Bg3, Cg1, and Cg2 horizons); a particle-size control section from 10 to 40 inches. Iffgulch soils have a frigid temperature regime and an aquic moisture regime.
ADDITIONAL DATA: NSSL data S93MT-089-002.