LOCATION FLINTCREEK         MT 
Established Series
Rev. HAL-JAL
05/2003

FLINTCREEK SERIES


The Flintcreek series consists of very deep, very poorly drained soils that formed in alluvium. These soils are on glacial outwash plains, stream terraces and floodplains. Slopes are 0 to 2 percent. Mean annual precipitation is about 15 inches, and mean annual temperature is about 42 degrees F.

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

TYPICAL PEDON: Flintcreek loam, in pasture (colors are for moist colors unless otherwise noted).

Oi--0 to 2 inches; decomposed organic matt.

A--2 to 14 inches; very dark gray (10YR 3/1) loam, dark gray (10YR 4/1) dry; many very fine and fine distinct brownish yellow (10YR 6/8) redox concentrations; moderate fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine interstitual pores; neutral (pH 6.6); gradual wavy boundary. (10 to 15 inches thick)

Bg--14 to 26 inches; black (10YR 2/1) stratified gravelly loam and gravelly silt loam, dark gray (10YR 4/1) dry; many very fine distinct brownish yellow (10YR 6/8) redox concentrations; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; few very fine interstitial pores; 5 percent cobbles and 10 percent pebbles; neutral (pH 6.6); clear smooth boundary. (10 to 25 inches thick)

2Cg--26 to 60 inches; very dark grayish brown (10YR 3/2) extremely gravelly loamy sand, gray (10YR 5/1) dry; many very fine distinct brownish yellow (10YR 6/8) redox concentrations; single grain; loose, nonsticky and nonplastic; common very fine roots; 15 percent cobbles and 45 percent pebbles; neutral (pH 6.8).

TYPE LOCATION: Granite County, Montana; 1,000 feet east and 2,300 feet north of the SW corner of sec. 26, T. 6 N., R. 14 W.

RANGE IN CHARACTERISTICS:

Soil temperature - 41 to 46 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 24 to 60 inches.
Depth to 2Cg horizon - 20 to 40 inches.
Depth to seasonal high water table - 0 to 12 inches.

A horizon - Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Clay content: 18 to 27 percent
Redox concentrations: common to many distinct or prominent 10YR 5/8, 10YR 6/8, 10YR 5/6, or 10YR 6/6
Rock fragments: 0 to 15 percent; 0 to 5 percent cobbles; 0 to 10 percent pebbles
Reaction: pH 6.6 to 7.3

Bg horizon - Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 or 2
Texture: loam, silt loam, sandy loam or clay loam
Clay content: 18 to 35 percent
Redox concentrations: common to many distinct or prominent 10YR 5/8, 10YR 6/8, 10YR 5/6, or 10YR 6/6
Rock fragments: 15 to 35 percent; 5 to 10 percent cobbles; 10 to 25 percent pebbles
Reaction: pH 6.6 to 7.3

2Cg horizon - Value: 4, 5 or 6 dry, 3, 4 or 5 moist
Chroma: 1 or 2
Texture: loamy sand or sand
Clay content: 5 to 15 percent
Redox concentrations: common to many, distinct or prominent 10YR 5/8, 10YR 6/8, 10YR 5/6, or 10YR 6/6
Rock fragments: 50 to 80 percent--10 to 20 percent cobbles, 40 to 60 percent pebbles
Reaction: 6.6 to 7.3

COMPETING SERIES:

Degarmo (OR) - is poorly or somewhat poorly drained with the water table at a depth of 1 to 2.5 feet from the surface.

Dula (NM) is poorly drained with the water table at a depth of 1 to 3.5 feet from the surface.

GEOGRAPHIC SETTING:

Landform - glacial outwash plains, stream terraces and flood plains.
Elevation - 3,600 to 6,200 feet.
Slope - 0 to 2 percent.
Parent material - alluvium .
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 19 inches.
Mean annual air temperature - 39 to 44 degrees F.
Frost-free period - 70 to 105 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Nythar soil which is fine-loamy and on similar landform positions.

DRAINAGE AND PERMEABILITY: Very poorly drained, moderate permeability above the 2C horizon, very rapid below.

USE AND VEGETATION: Flintcreek soils are primarily used for pasture and wildlife habitat. The potential native vegetation is mainly tall reedgrass, tufted hairgrass, blue-eye grass and willows.

DISTRIBUTION AND EXTENT: Flintcreek soils are inextensive in western Montana valleys.

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

SERIES ESTABLISHED: Granite County, Montana, 1997.

REMARKS: Soil interpretive record: MT1597. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from 2 to 60 inches (A, Bg, 2Cg horizons); a particle-size control from 12 to 42 inches (A, Bg and 2Cg horizons). Flintcreek soils have a frigid temperature regime and an aquic moisture regime.


National Cooperative Soil Survey
U.S.A.