LOCATION ENTENTE            MT
Established Series
Rev. JAL-RJE
03/2002

ENTENTE SERIES


The Entente series consists of very deep, well drained soils that formed in alluvium and lacustrine deposits. These soils are on lake terraces and stream terraces. Slopes are 0 to 15 percent. Mean annual precipitation is about 20 inches, and mean annual temperature is about 42 degrees F.

TAXONOMIC CLASS: Coarse-silty, mixed, superactive, frigid Lamellic Haplustepts

TYPICAL PEDON: Entente silt loam, open stand of ponderosa pine. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 1 inch; forest litter and partly decomposed conifer leaves and twigs.

A--1 to 4 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure; soft, very friable; common very fine, fine and many medium roots; many very fine and fine tubular pores; moderately acid (pH 6.0); clear smooth boundary. (2 to 5 inches thick)

E--4 to 9 inches; pinkish gray (7.5YR 7/2) silt loam, brown (7.5YR 4/2) moist; massive; soft, very friable; common very fine, fine and medium roots; many very fine, fine and few medium tubular pores; slightly acid (pH 6.5); clear irregular boundary. (4 to 10 inches thick)

E and Bt--9 to 13 inches; E part 85 percent, pinkish gray (7.5YR 7/2) silt loam, brown (7.5YR 4/2) moist; Bt part 15 percent, lamellae 1/8 to 1 inch thick that are light brown (7.5YR 6/4) silt loam, brown (7.5YR 4/4) moist; massive; hard, very friable, slightly sticky; common very fine, fine and medium roots; many very fine, fine and few medium pores; neutral (pH 7.0); clear broken boundary. (4 to 8 inches thick)

BC--13 to 29 inches; pink (7.5YR 7/3) silt loam, brown (7.5YR 4/3) moist; massive; soft, very friable, common very fine, fine and medium roots; many very fine, common fine and medium tubular pores; moderately alkaline (pH 8.0); gradual smooth boundary.

C1--29 to 46 inches; very pale brown (10YR 7/3) silt loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, very friable; few fine and medium roots; common very fine, fine and few medium tubular pores; moderately alkaline (pH 8.0); clear wavy boundary.

C2--46 to 60 inches; very pale brown (10YR 7/3) silt loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable; few fine and medium roots; common very fine, fine and few medium tubular pores; weakly effervescent; moderately alkaline (pH 8.0).

TYPE LOCATION: Mineral County, Montana; 60 feet east and 30 feet north of the SW corner of Sec. 19, T. 17 N., R. 26 W.

RANGE IN CHARACTERISTICS:

Soil temperature - 42 to 47 degrees F.
Moisture control section - approximately between the depths of 4 and 12 inches.

A horizon - Hue: 7.5YR or 10YR
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2, or 3
Texture: silt loam or very fine sandy loam
Clay content: 5 to 15 percent
Reaction: pH 6.1 to 7.3

E horizon - Hue: 7.5YR, 10YR or 2.5Y
Value: 5, 6, or 7 dry; 4, or 5 moist
Chroma: 2 or 3
Texture: silt loam or very fine sandy loam
Clay content: 5 to 15 percent
Reaction: pH 6.1 to 7.3

E and Bt horizon - Hue: 7.5YR, 10YR, or 2.5Y
Value: E part 5, 6, or 7, Bt part 4, 5, or 6 dry; E part 4 or 5, Bt part 4 or 5 moist
Chroma: 2, 3, or 4
Texture: silt loam or very fine sandy loam
Clay content: 5 to 15 percent
Reaction: pH 6.6 to 7.3

BC and C horizons - Hue: 7.5 YR, 10YR, or 2.5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 3 or 4
Texture: silt loam or very fine sandy loam
Clay content: 5 to 15 percent
Reaction: pH 7.4 to 7.8

COMPETING SERIES: These are the similar Ambrant, Wildgen and Winkler series in other families. Ambrant soils are coarse-loamy. Wildgen and Winkler soils are loamy-skeletal.

GEOGRAPHIC SETTING: The Entente soils are on lake terraces and stream terraces. Elevations are 3,500 to 4,500 feet. Slopes are 0 to 15 percent. These soils formed in silt loam deposits. The climate is characterized by long, cold winters; moist springs; and early summers. Mean annual precipitation is 16 to 20 inches. Mean annual temperature is 40 to 45 degrees F. The frost-free period is 90 to 120 days.

DRAINAGE AND PERMEABILITY: Well drained; moderate to moderately rapid permeability.

USE AND VEGETATION: Entente soils are used mainly for forest products; small areas have been cleared for hayland or pasture. Potential native vegetation is mainly ponderosa pine, western larch, and Douglas-fir dominating the overstory with Oregon-grape, rose, spiraea, serviceberry, snowberry, ninebark, kinnikinnick, balsamroot, strawberry, western yarrow, pussytoes, and tall grass in the understory.

DISTRIBUTION AND EXTENT: Entente soils are inextensive in valleys in the Rocky Mountains in western Montana.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Mineral County (St. Regis-Ninemile Area), Montana, 1970.

REMARKS: Soil Interpretations Record: MT0533.
Diagnostic horizons and features recognized in this pedon are:
An ochric epipedon - a thin mollic colored surface layer 3 inches thick (A horizon);
An albic horizon from 4 to 9 inches (E horizon);
A horizon with lamellae from 9 to 13 inches (E and Bt horizon);
A cambic horizon from 9 to 29 inches (E and Bt, and BC horizons);
Particle-size control section from 11 to 41 inches (part of E and Bt horizon, BC and C horizons).


National Cooperative Soil Survey
U.S.A.