LOCATION EAGLETON MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Cumulic Endoaquolls
TYPICAL PEDON: Eagleton loam, in grass hay (colors are for moist soil unless otherwise noted).
Ap--0 to 6 inches; very dark brown (10YR 2/2) loam, dark grayish brown (10YR 4/2) dry; few fine distinct dark yellowish brown (10YR 4/4) redox concentrations; strong medium and coarse granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine and common medium roots; neutral (pH 7.2); abrupt smooth boundary. (4 to 8 inches thick)
A2--6 to 19 inches; very dark grayish brown (10YR 3/2) loam consisting of thin layers of fine sandy loam and clay loam, grayish brown (10YR 5/2) dry; common fine distinct dark yellowish brown (10YR 4/4) redox concentrations; weak fine subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common fine and very fine and few medium roots; common very fine tubular pores; neutral (pH 7.2); clear wavy boundary. (5 to 20 inches thick)
A3--19 to 38 inches; very dark grayish brown (10YR 3/2) loam consisting of thin layers of fine sandy loam and clay loam, dark grayish brown (10YR 4/2) dry; common fine and medium distinct dark yellowish brown (10YR 4/6) redox concentrations; weak fine and medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; few fine and very fine roots; common very fine tubular pores; slightly alkaline (pH 7.6); clear wavy boundary. (14 to 24 inches thick)
Cg--38 to 60 inches; black (5Y 2.5/1) loam consisting of thin layers of fine sandy loam and silty clay loam, dark gray (5Y 4/1) dry; massive; hard, friable, slightly sticky and slightly plastic; common very fine tubular pores; neutral (pH 7.0).
TYPE LOCATION: Chouteau County, Montana; 1,900 feet west and 1,100 feet south of the NE corner of sec. 18, T. 27 N., R. 17 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 38 to 46 degrees F.
Moisture control section - between 4 and 12 inches, has aquic conditions, redoximorphic features, and endosaturation.
Mollic epipedon thickness - 24 to 60 inches.
Depth to seasonal high water table - 12 to 24 inches during the period from November to June and frozen during winter months.
Some pedons have a Bw horizon in place of the A3 horizon.
Ap horizon - Hue: 10YR
Value: 3, 4, or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Redoximorphic features: none or few; Hue 10YR; Value 5 or 6 dry, 4 moist; Chroma 4 or 6
Texture: loam or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.1 to 7.8
A2 horizon - Hue: 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 or 2
Redoximorphic features: few of common; Hue 10YR; Value 5 or 6 dry, 4 moist; Chroma 4 or 6
Texture: loam, clay loam, or silty clay loam consisting of thin layers of sandy loam, fine sandy loam, sandy clay loam, or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.1 to 7.8
A3 horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 or 2
Redoximorphic features: common or many; Hue 10YR; Value 5 or 6 dry, 4 moist; Chroma 4, 6, or 8
Texture: loam, clay loam or sandy clay loam consisting of thin layers of sandy loam, fine sandy loam, sandy clay loam, or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.1 to 7.8
Cg horizon - Hue: 5Y, N
Value: 4, 5, 6 or 7 dry; 2, 3, 4, or 5 moist
Redoximorphic features: none to common; Hue 10YR; Value 5 or 6 dry, 4 moist; Chroma 4 or 6
Texture: loam, clay loam or sandy clay loam consisting of thin layers of sandy loam, fine sandy loam, sandy clay loam, clay loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
Cometcrik (MT) - has a lithologic discontinuity at 40 to 60 inches.
Kovich (UT) - has a lithologic discontinuity at 24 to 38 inches.
Lakepark (MN) - has free carbonates at 25 to 50 inches.
Lobe (CO) - does not have redox concentrations above 30 inches.
Mannixlee (MT) - has skeletal material below a depth of 40 inches.
Marshbrook (SD) - does not have stratifications in the particle-size control section; has a regular decrease in organic matter.
Nythar (MT) - has Bg horizons; is not stratified in the particle-size control section; is very poorly drained.
Welch (NV) - has a high component of vitric pyroclastic materials in the control section; has a water table at or near surface in late winter and early spring; is not frozen all of the winter months; does not have redox concentrations in the mollic epipedon.
GEOGRAPHIC SETTING:
Landform - flood plains and drainageways.
Elevation - 3,000 to 6,000 feet.
Slope- 0 to 15 percent.
Parent material - alluvium derived from mixed sources including igneous and sedimentary rocks.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 14 to 19 inches.
Mean annual air temperature - 36 to 45 degrees F.
Frost-free period - 80 to 120 days.
DRAINAGE AND PERMEABILITY: Poorly drained; moderate permeability.
USE AND VEGETATION: Eagleton soils are used mainly for range and native grass hay production. Potential native vegetation is mainly basin wildrye, northern reedgrass, prairie cordgrass, slender wheatgrass, Canada wildrye, sedges, rushes, willows, chokecherry, and rose.
DISTRIBUTION AND EXTENT: Eagleton soils are of small extent in north-central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Chouteau County, Montana, 1992.
REMARKS: Soil interpretation record: MT1345. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the surface to 60 inches; mottled horizons from the surface to 38 inches (Ap, A2, and A3 horizons); a gleyed horizon from 38 to 60 inches (Cg horizon); and a particle-size control section from 10 to 40 inches. Eagleton soils have a frigid temperature regime and aquic conditions.