LOCATION VIGILANTE MT
Established Series
Rev. DES-JAL-EMM
04/2014
VIGILANTE SERIES
The Vigilante series consists of deep, well drained soils that formed in colluvium or slope alluvium deposited over hard fractured shale, siltstone or argillite bedrock. These soils are on alluvial fans, hills and ridges. Slopes are 8 to 50 percent. Mean annual precipitation is about 16 inches, and mean annual temperature is about 40 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Haplustolls
TYPICAL PEDON: Vigilante channery loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 7 inches; brown (7.5YR 4/2) channery loam, dark brown (7.5YR 3/2) moist; moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; 25 percent channers; slightly alkaline (pH 7.4); clear wavy boundary. (7 to 11 inches thick)
Bw1--7 to 16 inches; brown (10YR 5/3) very channery loam, brown (7.5YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and fine and few medium roots; common very fine and fine pores; 5 percent flagstones and 50 percent channers; neutral (pH 7.2); gradual wavy boundary.
Bw2--16 to 34 inches; pale brown (10YR 6/3) extremely channery loam, brown (10YR 4/3) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and fine and few medium roots; common medium pores; 5 percent flagstones and 65 percent channers; neutral (pH 7.0); gradual irregular boundary. (Combined thickness of Bw horizons is 20 to 30 inches).
BC--34 to 46 inches; very pale brown (10YR 7/3) extremely channery loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; common fine pores; 10 percent flagstones and 70 percent channers; neutral (pH 7.0); gradual wavy boundary. (10 to 15 inches thick)
R--46 inches; hard pale brown (10YR 6/3) highly fractured shale.
TYPE LOCATION: Jefferson County, Montana; 800 feet south and 2,675 feet west of the northeast corner of sec. 19, T. 2 N., R. 3 W.
RANGE IN CHARACTERISTICS:
Annual soil temperature - 38 to 44 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 11 inches.
Depth to bedrock - 40 to 60 inches.
A horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry
Chroma: 2 or 3, dry or moist
Clay content: 12 to 27 percent
Texture: loam or sandy loam
Rock fragments: 15 to 35 percent--0 to 10 percent flagstones; 15 to 25 percent channers
Reaction: pH 6.6 to 7.8
Bw1 horizon
Hue: 7.5YR or 10YR
Value: 5 or 6 dry; 4 or 5 moist:
Chroma: 2 or 3, dry or moist
Clay content: 15 to 27 percent
Texture: loam or sandy loam
Rock fragments: 25 to 60 percent--0 to 10 percent flagstones and 25 to 50 percent channers
Reaction: pH 6.6 to 7.8
Bw2 horizon
Hue: 7.5YR, 10YR or 2.5Y
Value: 5, 6 or 7 dry; 4 or 5 moist:
Chroma: 2, 3 or 4, dry or moist
Texture: loam or sandy loam
Clay content: 15 to 27 percent
Rock fragments: 35 to 75 percent--0 to 10 percent flagstones; 35 to 65 percent channers
Reaction: pH 6.6 to 7.8
BC horizon
Hue: 7.5YR, 10YR or 2.5Y
Value: 5, 6 or 7 dry; 4 or 5 moist:
Chroma: 2, 3 or 4, dry or moist
Texture: loam or sandy loam
Clay content: 10 to 15 percent
Rock fragments: 35 to 85 percent--5 to 15 percent flagstones; 30 to 70 percent channers
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
Aguja (NM) - is 20 to 40 inches deep to a paralithic contact
Finleypoint (MT) - is very deep
Flott (MT) - is very deep
Kutler (CO) - is 20 to 40 inches to a paralithic contact
Labre (MT) - is very deep
Labre (MT) - does not have a lithic contact; has a calcic horizon.
Perma (MT) - does not have a lithic contact; is somewhat excessively drained.
Peso (NM) - 20 to 40 inches deep to bedrock; has horizon of secondary carbonate accumulation.
Pesowyo (WY) - 20 to 40 inches deep to bedrock; has horizon of secondary carbonate accumulation.
Sandia (NM) - more than 50 percent cobbles and stones in the control section; chroma of 1 in the mollic epipedon.
Slimbutte (SD) - does not have a lithic contact; has horizon of secondary carbonate accumulation.
Subwell (MT) - does not have a lithic contact; has a calcic horizon.
Towave (UT) - does not have a lithic contact above 60 inches; has horizons of secondary carbonate accumulation.
Veatch (CO) - 20 to 40 inches deep to bedrock; has horizon of secondary carbonate accumulation.
Walstead () -
Wanagan (ND) - does not have a lithic contact; has horizons of secondary carbonate accumulation.
Wimper (MT) - does not have a lithic contact; has horizons of secondary carbonate accumulation.
GEOGRAPHIC SETTING:
Landform - alluvial fans, hills and ridges.
Elevation - 4,400 to 6,500 feet.
Slope - 8 to 50 percent.
Parent material - colluvium or slope alluvium deposited over hard highly fractured shale, siltstone, or argillite bedrock.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual temperature - 38 to 42 degrees F.
Frost-free period - 70 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability to a depth of 16 inches and moderately rapid below.
USE AND VEGETATION: Vigilante soils are primarily used for rangeland. The potential native vegetation is mainly bluebunch wheatgrass, Idaho fescue, needleandthread, sandberg bluegrass, western yarrow, big sagebrush and Rocky Mountain juniper. Some areas have a widely scattered overstory of Douglas-fir, limber pine and Rocky Mountain juniper.
DISTRIBUTION AND EXTENT: Vigilante soils are of small extent in southwestern Montana. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the surface to 7 inches (A horizon)
Cambic horizon - from 7 to 34 inches (Bw1 and Bw2 horizons)
Particle size control section - from 10 to 40 inches (Bw1, Bw2 and BC horizons)
Lithic contact to hard fractured shale bedrock - at 46 inches (R horizon).
Soil interpretation record: MT1586.
Vigilante soils have a frigid temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.