LOCATION TRUMANCREEK MTTentative Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, nonacid, frigid Typic Endoaquepts
TYPICAL PEDON: Trumancreek loam, forested (colors are for dry soil unless otherwise noted)
A--0 to 18 cm; grayish brown (10YR 5/2) loam, dark grayish brown (10YR 4/2) moist; weak fine and medium subangular blocky structure parting to weak medium and coarse granular; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium and coarse roots; common very fine and fine dendritic tubular pores; neutral (pH 6.8); clear wavy boundary. (10 to 30 cm thick)
Bw1--18 to 41 cm; pale brown (10YR 6/3) silt loam, brown (10YR 5/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, fine, medium and coarse and few very coarse roots; common very fine and fine dendritic tubular pores; 5 percent gravel; neutral (pH 6.8); gradual wavy boundary.
Bw2--41 to 56 cm; light brownish gray (10YR 6/2) silt loam, grayish brown (10YR 5/2) dry; weak fine and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few distinct dark yellowish brown (10YR 4/4) redox concentrations; common fine, medium and coarse and few very coarse roots; common very fine and fine dendritic tubular pores; 5 percent gravel; neutral (pH 6.8); clear wavy boundary. (Combined thickness of Bw horizons is 15 to 46 cm)
C1--56 to 71 cm; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; common prominent dark yellowish brown (10YR 4/6) redox concentrations; common fine and medium roots; common very fine and fine dendritic tubular pores; 10 percent gravel; neutral (pH 6.8); clear wavy boundary. (10 to 25 cm thick)
2C2--71 to 89 cm; light yellowish brown (2.5Y 6/3) extremely gravelly loamy coarse sand, light olive brown (2.5Y 5/3) moist; single grain; loose, nonsticky and nonplastic; many prominent dark yellowish brown (10YR 4/6) redox concentrations; common fine and medium roots; 50 percent gravel and 10 percent cobbles; neutral (pH 6.8); clear wavy boundary. (15 to 51 cm thick)
3Cg1--89 to 94 cm; gray (2.5Y 6/1) gravelly clay loam, dark gray (2.5Y 4/1) moist; hard, firm, moderately sticky and moderately plastic; common prominent dark yellowish brown (10YR 4/6) redox concentrations; few fine and medium roots; common very fine and fine dendritic tubular pores; 20 percent gravel; neutral (pH 7.0); clear wavy boundary. (0 to 10 cm thick)
4Cg2--94 to 152 cm; gray (5Y 6/1) extremely gravelly loamy coarse sand, dark gray (5Y 4/1) moist; single grain; loose, nonsticky and nonplastic; few fine and medium roots; 60 percent gravel and 10 percent cobbles; neutral (pH 7.2).
TYPE LOCATION: Flathead County, Montana; 1500 feet west and 1600 feet north of the SE corner of section 20, T. 27 N., R.22 W. Kila topographic quadrangle. UTM NAD 83 Zone 11: Northing 5328490, Easting 689525.
RANGE IN CHARACTERISTICS:
Soil temperature - 5 to 7 degrees C.
Depth to 2C horizon - 64 to 89 cm.
Depth to seasonal high water table - 30 to 61 cm (April to June).
A horizon - Value: 4, 5 or 6 dry, 3 or 4 moist
Chroma: 2 or 3
Texture: loam, silt loam, very fine sandy loam
Clay content: 8 to 18 percent
Rock fragments: 0 to 5 percent gravel
Reaction: pH 6.1 to 7.8
Bw horizons Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Texture: silt loam, loam, or very fine sandy loam
Clay content: 8 to 18 percent
Rock fragments: 0 to 5 percent gravel
Reaction: pH 6.1 to 7.8
C1 horizon - Hue: 2.5Y or 10YR
Value: 5, 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Clay content: 6 to 14 percent
Rock fragments: 0 to 5 percent gravel
Reaction: pH 6.1 to 7.8
2C2 horizon - Value: 6 or 7 dry; 4 or 5 moist
Texture: coarse sand, sand, loamy coarse sand, or loamy sand
Clay content - 0 to 8 percent
Rock fragments: 40 to 70 percent--5 to 15 percent cobbles, 35 to 55 percent gravel
Reaction: pH 6.1 to 7.8
3Cg horizon Hue: 2.5Y or 5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 1 or 2
Texture: loam, clay loam, or silty clay loam
Clay content - 20 to 35 percent
Rock fragments: 15 to 50 percent--0 to 15 percent cobbles, 15 to 35 percent gravel
Reaction: pH 6.1 to 7.8
4Cg horizon Hue: 5Y or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 1 or 2
Texture: coarse sand, sand, loamy coarse sand, or loamy sand
Clay content - 0 to 8 percent
Rock fragments: 60 to 80 percent--10 to 20 percent cobbles, 50 to 60 percent gravel
Reaction: pH 6.1 to 7.8
COMPETING SERIES: This is the Minocqua series. The Minocqua series is in a 710 to 838 mm precipitation zone, has saturation at or near the surface for long periods, and more than 50 percent of the matrix has redox depletions.
GEOGRAPHIC SETTING: Trumancreek soils are on low stream terraces and flood plains in glaciated mountain valleys. Elevations are 884 to 1250 m. Slopes are 0 to 4 percent. These soils form in alluvium. The climate is characterized by long, cold winters; moist springs; and warm, dry summers. Mean annual precipitation is 457 to 610 mm, much of which falls as snow or spring rain. Mean annual temperature is 3 to 7 degrees C. Frost-free period is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blackcreek, Idahocreek, Tallcreek, Foyslake, and Mcmannamy soils. Blackcreek and Idahocreek soils are poorly drained and occupy similar landscape positions. Tallcreek soils are moderately well drained and are on low stream terraces. Foyslake soils are well drained, have argillic horizons and are on adjacent north aspects. Mcmannamy soils are well drained, have argillic horizons and are on adjacent south aspects.
DRAINAGE AND PERMEABILITY: Poorly drained, moderate over rapid permeability.
USE AND VEGETATION: Trumancreek soils are used for timber production and wildlife habitat. Potential native vegetation is mainly Engelmann spruce, Douglas Fir, water birch, and black cottonwood with an understory of queencup beadlily, twinflower, bunchberry dogwood, western meadowrue, sweetscented bedstraw, bluejoint, snowberry, willow, alder, black hawthorn, and redosier dogwood.
DISTRIBUTION AND EXTENT: Trumancreek soils are of limited extent in the valleys of northwestern Montana. MLRA 43A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Flathead County, Montana 2005. The name is from Truman Creek, which is a tributary of Ashley Creek in northwest Montana.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 18 cm (A horizon);
Cambic horizon - 18 to 56 cm (Bw1 and Bw2 horizons); and
Particle-size control section from 25 to 100 cm (Bw1, Bw2, C1, 2C2, 3Cg1, 4Cg2 horizons).
Trumancreek soils have an aquic moisture regime and a frigid temperature regime.