LOCATION CASEYPEAK MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Lithic Haplocryepts
TYPICAL PEDON: Caseypeak gravelly coarse sandy loam, bouldery forested (colors are for dry soil unless otherwise noted).
Oi--0 to 1.5 inches; partially decomposed needles, twigs, and leaves. (1/2 to 3 inches thick)
E--1.5 to 6 inches; light brownish gray (10YR 6/2) gravelly coarse sandy loam, brown (10YR 5/3) moist; moderate medium granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; many very fine and fine and few medium pores; 20 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (3 to 6 inches thick)
Bw1--6 to 12 inches; brown (10YR 5/3) very gravelly coarse sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; many very fine and few fine tubular and interstitial pores; 40 percent gravel; neutral (pH 6.6); gradual wavy boundary. (4 to 8 inches thick)
Bw2--12 to 17 inches; pale brown (10YR 6/3) very gravelly coarse sandy loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, common fine and few medium roots; many very fine and few fine tubular and interstitial pores; 40 percent gravel; neutral (pH 6.7); clear wavy boundary. (3 to 6 inches thick)
Cr--17 to 20 inches; light yellowish brown (2.5Y 6/4) decomposed granite bedrock (grus) that crushes to very gravelly loamy coarse sand; neutral (pH 6.8). (2 to 18 inches thick)
R--20 inches; hard granite bedrock.
TYPE LOCATION: Jefferson County, Montana; 1,550 feet north and 1,100 feet west of the SE corner of sec. 19, T. 4 N., R. 3 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 36 to 42 degrees F.
Moisture control section - between 4 and 12 inches or to the lithic contact when bedrock is less than 12 inches.
Base saturation - greater than 60 percent throughout.
Depth to Cr horizon - 10 to 18 inches.
Depth to bedrock - 12 to 20 inches.
Surface stones or boulders - 0 to 50 percent
A thin A horizon is allowed.
E horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2 or 3
Texture: coarse sandy loam, sandy loam, or loamy coarse sand
Clay content: 10 to 20 percent
Rock fragments: 10 to 60 percent--0 to 15 percent cobbles and stones, 10 to 50 percent gravel
Reaction: pH 5.6 to 6.5
Bw1 horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: coarse sandy loam, sandy loam, or sandy clay loam
Clay content: 10 to 22 percent
Rock fragments: 35 to 60 percent gravel (mainly less than 7mm in diameter)
Reaction: pH 6.1 to 7.3
Bw2 horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4
Texture: coarse sandy loam, sandy loam, or sandy clay loam
Clay content: 10 to 22 percent
Rock fragments: 35 to 60 percent gravel (mainly less than 10mm in diameter)
Reaction: pH 6.1 to 7.3
COMPETING SERIES:
Banker (WA) - has a xeric moisture regime.
Cobblank (AK) - has a subarctic climate.
Cowood (MT) - does not have a paralithic contact of grus above a lithic contact of granite; has a udic moisture regime.
Hechtman (WY) - slightly to strongly acid throughout; has a udic moisture regime; does not have a paralithic contact over the rhyolite rock.
Jarbidge (NV) - has a xeric moisture regime.
Luckiamute (OR) - has 27 to 35 percent clay in the particle-size control section; has a udic moisture regime; very strongly acid throughout.
Merino (CO) - does not have a cambic horizon.
Pendergrass (CO) - has hue of 5YR or redder throughout.
Sigbird (MT) - does not have a paralithic contact of grus above the lithic contact; formed in colluvium or residuum from shale.
Treebutte (WA) - has a xeric moisture regime.
GEOGRAPHIC SETTING:
Landform- mountains; hills.
Elevation - 5,500 to 8,000 feet.
Slope - 2 to 60 percent.
Parent material - residuum derived from granite and other coarse grained igneous rocks.
Climate - long, cold winters; cool, moist springs; short, cool summers.
Mean annual precipitation - 15 to 30 inches.
Mean annual air temperature - 34 to 40 degrees F.
Frost-free period - 30 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, moderately rapid permeability.
USE AND VEGETATION: Caseypeak soils are primarily used for timber production and wildlife habitat. The potential native vegetation is mainly Douglas fir, lodgepole pine, pinegrass, white spiraea, common snowberry, russet buffaloberry, common juniper, Kinnikinnick, raceme pussytoes, Oregongrape, heartleaf arnica, rough fescue, and Idaho fescue.
DISTRIBUTION AND EXTENT: Caseypeak soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Soil interpretation record: MT1594, MT3070, MT3073. Diagnostic horizons and features recognized in this pedon are: a layer of partially decomposed needles, twigs, and leaves from 1 1/2 inches to the mineral soil surface (Oi horizon); an ochric epipedon from the mineral surface to 7 inches, mixed (E, Bw horizons); a cambic horizon from 5 to 16 inches (Bw1, Bw2 horizon); a layer of decomposed granite (grus) from 16 to 19 inches (Cr horizon); hard granite bedrock at 19 inches (R horizon); a particle-size control section from 10 to 16 inches (Bw, Bw2 horizons). Caseypeak soils have a cryic temperature regime and an ustic moisture regime.
The 3/2008 description reflects a change in classification from Loamy-skeletal, mixed, superactive Lithic Eutrocryepts to Loamy-skeletal, mixed, superactive Lithic Haplocryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.