LOCATION CLUGULCH MT
Established Series
Rev: TJK-JAL-EMM
07/2012
CLUGULCH SERIES
The Clugulch series consists of very shallow, well drained soils that formed in residuum derived from granite or other coarse grained igneous rocks. These soils are on bedrock-floored plains, mountains, and hills. Slopes are 2 to 70 percent. Mean annual precipitation is about 17 inches, and mean annual air temperature is about 38 degrees F.
TAXONOMIC CLASS: Loamy, mixed, superactive Lithic Haplocryepts
TYPICAL PEDON: Clugulch sandy loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 inches to 2; partially decomposed twigs, needles, bark, and lichens. (1 to 3 inches thick)
A--2 to 5 inches; dark grayish brown (10YR 4/2) sandy loam, black (10YR 2/1) moist; moderate fine granular structure; soft, very friable, nonsticky and moderately plastic; few very fine and fine roots; many very fine pores; 5 percent gravel; neutral (pH 6.7); clear wavy boundary. (1 to 4 inches thick)
Bw--5 to 9 inches; light brownish gray (10YR 6/2) coarse sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; few very fine pores; 10 percent gravel; slightly acid (pH 6.5); abrupt wavy boundary. (3 to 6 inches thick)
R--9 inches; hard granite bedrock.
TYPE LOCATION: Silver Bow County, Montana; 2,000 feet south and 1,350 feet west of the NE corner of sec. 5, T. 1 S., R. 6 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 38 to 42 degrees F.
Moisture control section - 4 inches to the lithic contact.
Depth to bedrock - less than 10 inches.
Surface stones or boulders - 0 to 0.1 percent
The surface, when mixed to a depth of 7 inches, does not meet the color requirements for a mollic epipedon.
Some pedons have a Cr horizon above the R horizon.
A horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry
Chroma: 1, 2, or 3
Texture: sandy loam or coarse sandy loam
Clay content: 10 to 18 percent
Rock fragments: 0 to 25 percent gravel, 0 to 5 percent cobbles
Reaction: pH 6.1 to 7.5
Bw horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: sandy loam or coarse sandy loam, more than 35 percent fine and coarser sand
Clay content: 5 to 15 percent
Rock fragments: 5 to 35 percent gravel (mainly less than 10 mm in diameter)
Reaction: pH 6.1 to 7.5
C horizon present in some pedons.
COMPETING SERIES:
Clinetop (CO) - has more than 18 percent clay in the particle-size control section; is medium to slightly acid throughout; has precipitation range of 28 to 35 inches.
Goodview (AK) - have an umbric epipedon.
Liesnoi (AK) - has a silt loam loess mantle over bedrock; has a udic or wetter moisture regime.
Noname (OR) - has more than 18 percent clay in the particle-size control section; does not have an O horizon.
Olathe (CO) - has less than 35 percent fine and coarser sand in the particle-size control section; has 24 to 28 inches of precipitation; is at elevations of 9,000 feet and higher.
GEOGRAPHIC SETTING:
Landform - bedrock-floored plains; mountains; hills.
Elevation - 5,500 to 7,000 feet.
Slope - 2 to 70 percent.
Parent material - residuum derived from granite or other coarse grained igneous rocks.
Climate - long, cold winters; cool, moist springs; short, cool summers.
Mean annual precipitation - 15 to 24 inches.
Mean annual air temperature - 36 to 40 degrees.
Frost free season - 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability.
USE AND VEGETATION: Clugulch soils are primarily used for timber production, understory grazing, watersheds, and as wildlife habitat. The native vegetation is Douglas fir, lodgepole pine, and common juniper with a sparse understory of heartleaf arnica, Idaho fescue, spirea, and woods rose.
DISTRIBUTION AND EXTENT: Clugulch soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Silver Bow County portion of the Jefferson Soil Survey area, Montana, 1998.
REMARKS: Soil interpretation record: MT1596, MT3075.
Diagnostic horizons and features recognized in this pedon are:
A layer of partially decomposed forest litter from 2 inches to the mineral soil surface (Oi horizon);
Ochric epipedon - from the soil surface to 7 inches (A, Bw horizons);
Cambic horizon - from 3 to 7 inches (Bw horizon);
Lithic contact - hard granite bedrock at 7 inches (R horizon);
Particle-size control section from 0 to 7 inches (A, Bw horizons).
Clugulch soils have a cryic temperature regime and an ustic moisture regime.
The 3/2008 description reflects a change in classification from Loamy, mixed, superactive Lithic Eutrocryepts to Loamy, mixed, superactive Lithic Haplocryepts due to revision of the cryepts great groups and subgroups.
National Cooperative Soil Survey
U.S.A.