LOCATION LAMOOSE                 MT

Established Series
Rev. BDD-KTS-RJS
04/2011

LAMOOSE SERIES

The Lamoose series consists of very deep, poorly drained soils that formed in outwash and alluvium. These soils are on alluvial fans, stream terraces, outwash fans and flood plains. Slopes are 0 to 2 percent. Mean annual precipitation is about 16 inches, and mean annual air temperature is about 43 degrees F.

TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, calcareous, frigid Typic Endoaquolls

TYPICAL PEDON: Lamoose loam, cultivated (colors are for moist soil unless otherwise noted).

Ap--0 to 7 inches; black (10YR 2/1) loam, dark gray (10YR 4/1) dry; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine pores; strongly effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (7 to 12 inches thick)

Bg--7 to 19 inches; dark gray (10YR 4/1) loam, light gray (10YR 7/1) dry; common medium gray (10YR 5/1) redox depletions and dark yellowish brown (10YR 4/4) redox concentrations; weak coarse prismatic structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine pores; strongly effervescent; neutral (pH 7.2); abrupt wavy boundary. (7 to 18 inches thick)

2C--19 to 60 inches; dark grayish brown (10YR 4/2) very gravelly sand, light brownish gray (10YR 6/2) dry; single grain; loose, nonsticky and nonplastic; few fine roots; few fine pores; 50 percent gravel; slightly effervescent; neutral (pH 7.2).

TYPE LOCATION: Lake County, Montana; 2,350 feet east and 2,400 feet north of the SW corner of sec. 21, T. 17N., R. 20W.

RANGE IN CHARACTERISTICS:
Soil temperature - 43 to 47 degrees F.
Mollic epipedon thickness - 7 to 12 inches
Depth to a lithologic discontinuity - 14 to 27 inches
Depth to seasonal high water table - 6 to 24 inches

Note: Some pedons may have a Cg horizon. Also, some pedons may have a gravelly sandy loam transitional horizon above the 2C horizon. This horizon is less than 5 inches thick.

Ap horizon
Hue: 10YR, 2.5Y or 5Y; dry or moist
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2; dry or moist
Texture: loam, silt loam or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent gravel
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 6.6 to 8.4

Bg and Cg (if present) horizons
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 1 or 2; dry or moist
Texture: loam, silt loam, clay loam or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent gravel
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 6.6 to 8.4

2C horizon
Value: 5 or 7 dry; 4 or 5 moist
Chroma: 1 or 2; dry or moist
Texture: loamy sand or sand
Clay content: 0 to 10 percent
Rock fragments: 35 to 70 percent--35 to 65 percent gravel, 0 to 15 percent cobbles
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 6.6 to 8.4

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Landform - alluvial fans, stream terraces, outwash fans and flood plains
Elevation - 2,500 to 6,500 feet
Slope - 0 to 2 percent
Parent material - outwash and alluvium
Climate - long, cold winters; moist springs and falls; warm summers
Mean annual precipitation - 10 to 18 inches
Mean annual temperature - 39 to 45 degrees F.
Frost-free season - 70 to 120 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Poorly drained; moderate over rapid permeability.

USE AND VEGETATION: Lamoose soils are used mainly as nonirrigated hay and pasture. Potential native vegetation is tall reedgrasses, sedges, rushes, willows and cottonwood.

DISTRIBUTION AND EXTENT: It is of small extent in the intermountain valleys of northwestern Montana. MLRAs - 44A, 44B.

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

SERIES ESTABLISHED: Lake County, Montana, 1991; proposed in Lake County, Montana, 1970.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 7 inches (Ap horizon)
Lithologic discontinuity - at 19 inches (2C horizon
Particle-size control section - from 10 to 40 inches (part of Bg, part of 2C horizons)

Lamoose soils have a frigid temperature regime and an aquic moisture regime.

ADDITIONAL DATA: Soil interpretation records - MT0760, MT1325.

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National Cooperative Soil Survey
U.S.A.