LOCATION SHADOW MT
Established Series
Rev. JB-JJU-RJS
03/2012
SHADOW SERIES
The Shadow series consists of very deep, somewhat excessively drained soils that formed in colluvium and till derived from gneiss, schist, andesite and granite. These soils are on moraines, mountains and hills. Slopes are 8 to 75 percent. Mean annual precipitation is about 23 inches, and mean annual air temperature is about 39 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryepts
TYPICAL PEDON: Shadow extremely channery sandy loam, forested (colors are for dry soil unless otherwise noted).
Oe--0 to 1 inch; moderately decomposed forest litter. (1 to 3 inches thick)
A--1 to 4 inches; brown (10YR 5/3) extremely channery sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many fine, medium and coarse roots; many fine pores; 45 percent channers and 15 percent flagstones; slightly acid (pH 6.2); clear wavy boundary. (0 to 4 inches thick)
E--4 to 18 inches; pale brown (10YR 6/3) very channery sandy loam, brown (10YR 4/3) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; common fine, medium and coarse roots; common fine pores; 50 percent channers; slightly acid (pH 6.4); clear wavy boundary. (8 to 24 inches thick)
Bw--18 to 31 inches; brown (10YR 5/3) extremely channery sandy loam, brown (10YR 4/3) moist; weak fine blocky structure; slightly hard, very friable, nonsticky and nonplastic; common fine roots; common fine pores; 65 percent channers; neutral (pH 6.7); gradual smooth boundary. (10 to 20 inches thick)
BC--31 to 60 inches; pale brown (10YR 6/3) extremely channery sandy loam, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; 70 percent channers; neutral (pH 6.8).
TYPE LOCATION: Madison County, Montana; 150 feet south and 2,550 feet east of the northwest corner of sec. 13, T. 8S, R. 1E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 36 to 44 degrees F.
Base saturation - 60 to 100 percent
A horizon
Hue: 7.5YR or 10YR; dry or moist
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3; dry or moist
Texture: sandy loam or loam
Clay content: 5 to 15 percent
Rock fragments: 10 to 80 percent--10 to 55 percent channers or gravel, 0 to 25 percent flagstones, cobbles or stones
Reaction: pH 5.1 to 7.3
E horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: coarse sandy loam, sandy loam or loam
Clay content: 5 to 15 percent
Sand content: 55 to 80 percent--of which 5 to 15 percent is very fine sand and 15 to 40 percent is mica
Rock fragments: 40 to 70 percent--25 to 60 percent channers or gravel; 0 to 20 percent flagstones or cobbles
Reaction: pH 5.1 to 7.3
Bw horizon
Hue: 10YR, 7.5YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 or 3
Texture: coarse sandy loam, sandy loam, loam
Clay content: 5 to 15 percent
Sand content: 55 to 80 percent--of which 5 to 15 percent is very fine sand and 15 to 40 percent is mica
Rock fragments: 50 to 80 percent--35 to 70 percent channers or gravel, 0 to 35 percent flagstones or cobbles
Reaction: pH 5.1 to 7.8
BC horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: coarse sandy loam or sandy loam--with strata of sand or loamy sand in some pedons
Clay content: 5 to 15 percent
Sand content: 55 to 80 percent--of which 5 to 15 percent is very fine sand and 15 to 40 percent is mica
Rock fragments: 60 to 85 percent--35 to 75 percent channers or gravel, 0 to 30 percent flagstones or cobbles
Reaction: pH 5.1 to 7.8
COMPETING SERIES:
Ellena (MT) - are moderately deep to a paralithic and lithic contact
Elve (MT) - do not have 15 to 40 percent mica in the particle-size control section
Hiore (MT) - do not have an E horizon and do not have mica
Mawspring (MT) - do not have an E horizon and do not have mica
Pergrin (CO) - are moderately deep to a paralithic and lithic contact
Rubick (MT) - do not have mica
Scout (UT) - do not have 15 to 40 percent mica in the particle-size control section
Taglake (WY) - do not have 15 to 40 percent mica in the particle-size control section
GEOGRAPHIC SETTING:
Landform - moraines, mountains and hills
Elevation - 5,300 to 8,500 feet
Slope - 8 to 75 percent
Parent material - colluvium and till derived from gneiss, schist, andesite, and granite
Climate - long, cold winters; moist springs; cool summers
Mean annual precipitation - 15 to 30 inches
Mean annual temperature - 34 to 42 degrees F.
Frost-free season - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderately rapid permeability.
USE AND VEGETATION: Shadow soils are used mainly as woodland, recreation, wildlife habitat, and for watersheds. The potential native vegetation is Douglas-fir, lodgepole pine, and subalpine fir with an understory of pinegrass, common snowberry, elk sedge, ninebark, and heartleaf arnica.
DISTRIBUTION AND EXTENT: Shadow soils are moderately extensive in southwestern Montana. MLRAs - 43B, 44B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Madison County Area, Montana, 1983; proposed in Madison County Area, 1981.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 18 inches (Oe, A, E horizons)
Cambic horizon - from 18 to 31 inches (Bw horizon)
Particle-size control section - from 11 to 41 inches (part of E, Bw, part of BC horizons)
Shadow soils have a cryic temperature regime, an ustic moisture regime and an udic moisture subclass.
ADDITIONAL DATA: Soil interpretation records - MT0392, MT0708.
Classification Notes: The 3/2008 description reflects a change in classification from Loamy-skeletal, mixed, superactive Ustic Eutrocryepts to Loamy-skeletal, mixed, superactive Ustic Haplocryepts due to revision of the cryepts great groups and subgroups.
National Cooperative Soil Survey
U.S.A.