LOCATION HIGHWOOD MT
Tentative Series
IRD. KTS-EMM
02/2014
HIGHWOOD SERIES
The Highwood series consists of very deep, well drained soils that formed in colluvium and slope alluvium from mixed igneous rock sources. These soils occur on mountain slopes and structural benches. Slopes are 8 to 60 percent. Mean annual precipitation is about 700 mm, and the mean annual temperature is about 3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Eutric Haplocryalfs
TYPICAL PEDON: Highwood gravelly loam, in forest on a 35 percent northwest slope at an elevation of 1646 meters (Colors are for dry soil unless otherwise noted).
Oi--0 to 4 cm; slightly decomposed forest litter; clear smooth boundary. (3 to 6 cm thick)
A--4 to 12 cm; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, medium, and coarse roots; few very fine and fine irregular pores; 20 percent gravel and 5 percent cobbles; moderately acid (pH 5.6); clear smooth boundary. (5 to 15 cm thick)
BtE--12 to 33 cm; grayish brown (10YR 5/2) very cobbly clay loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine, fine, medium, and coarse roots; few very fine and fine tubular pores; few (10 percent) patchy clay films on faces of peds; 20 percent gravel and 20 percent cobbles; moderately acid (pH 5.8); gradual wavy boundary. (15 to 30 cm thick)
Bt1--33 to 64 cm; grayish brown (2.5Y 5/2) very cobbly clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine, fine, medium and coarse roots; common very fine and fine tubular pores; many (55 percent) distinct clay films on faces of peds; 25 percent gravel and 25 percent cobbles; moderately acid (pH 5.8); gradual wavy boundary. (20 to 40 cm thick)
Bt2--64 to 150 cm; olive brown (2.5Y 4/3) cobbly clay loam, dark olive brown (2.5Y 3/3) moist; moderate coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine, fine, medium, and coarse roots; common very fine and fine tubular pores; many (60 percent) distinct clay films on faces of peds; 15 percent gravel and 15 percent cobbles; moderately acid (pH 5.8).
TYPE LOCATION: Chouteau County, Montana; located 440 meters east and 252 meters south of the northwest corner of sec. 22, T. 20 N., R 9 E; Arrow Peak topographic quadrangle; UTM 12T, 532370e., 5259305n. NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 1 to 4 degrees C.
Moisture control section - between 10 and 30 cm.
Depth to argillic horizon - 10 to 20 cm
Some pedons have a thin E or EBt horizon above the BtE horizon.
Some pedons have a BC horizon below the lowest Bt horizon.
A horizon
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Clay content: 18 to 26 percent
Rock fragments: 15 to 40 percent--10 to 30 percent gravel, 0 to 10 cobbles
Reaction: pH 5.6 to 6.4
BtE horizon
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 3; dry or moist
Clay content: 22 to 35 percent
Texture: loam or clay loam
Rock fragments: 30 to 60 percent--10 to 40 percent gravel, 0 to 25 percent cobbles
Reaction: pH 5.6 to 6.4
Bt horizons
Hue: 10YR or 2.5Y
Value: 4 to 6 dry; 3 to 5 moist
Chroma: 2 to 3; dry or moist
Clay content: 27 to 35 percent
Rock fragments: 15 to 70 percent-15 to 50 percent gravel, 0 to 30 percent cobbles
Reaction: pH 5.6 to 6.4
COMPETING SERIES:
Frisco (CO) - have rock fragments that are dominantly stones
Helmville (MT) - have secondary calcium carbonate accumulation
Lonniebee (MT) - are moderately deep to a lithic contact
Needleton (CO) - have hues of 5YR or 2.5YR in the argillic horizon
Tamarron (CO) - are moderately deep to a paralithic contact
Tigeron (MT) - have argillic horizons consisting of lamellae
Watsondraw (WY) - do not have a BtE horizon
Worock (MT) - do not have an A horizon
GEOGRAPHIC SETTING: Landform - mountain slopes and structural benches. Elevation - 1370 to 2100 meters.
Slope - 8 to 60 percent.
Parent material - colluvium and slope alluvium from mixed igneous sources.
Climate - long, cold winters; moist springs; short warm summers.
Mean annual precipitation - 610 to 830 mm.
Mean annual air temperature - 1 to 4 degrees C.
Frost-free period - 40 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: well drained, moderate permeability.
USE AND VEGETATION: Highwood soils are used mainly for timber, wildlife and recreation. The vegetation is mainly Douglas-fir, lodgepole pine, quaking aspen, twinflower, spirea, huckleberry, common juniper, snowberry, Oregon grape, arnica (species), pinegrass, elksedge and other miscellaneous shrubs, grasses and forbs.
DISTRIBUTION AND EXTENT: Highwood soils are of limited extent in central Montana. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Chouteau County, Montana, 2013. Highwood series is named for a drainage on the Arrow Peak topographic quadrangle.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 12 cm (Oi and A horizons)
Argillic horizon - from 12 to 150 cm (BtE, Bt1, and Bt2 horizons)
Particle-size control section - from 12 to 62 cm (BtE and Bt1 horizons)
Highwood soils have a cryic temperature regime and an udic moisture regime.
Taxonomic version: Eleventh Edition, 2010.
National Cooperative Soil Survey
U.S.A.