LOCATION SCUDDER MT
Established Series
REV. KTS-JJU-RJS
01/2012
SCUDDER SERIES
The Scudder series consists of very deep, well drained soils that formed in slope alluvium, colluvium, slide deposits derived from limestone and other calcareous sedimentary rock. These soils occur on hills, mountain slopes, and debris avalanches. Slopes are 8 to 60 percent. Mean annual precipitation is about 480 mm, and the mean annual air temperature is about 3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, carbonatic Ustic Calcicryepts
TYPICAL PEDON: Scudder gravelly loam, in forestland on a 16 percent slope at an elevation of 2,300 meters (colors are for dry soil unless otherwise noted).
Oi--0 to 5 cm; slightly decomposed forest litter. (3 to 6 cm thick)
A--5 to 13 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 and medium roots; many very fine and fine dendritic tubular pores; 15 percent gravel; neutral (pH 7.2); clear smooth boundary. (8 to 15 cm thick)
Bw--13 to 28 cm; grayish brown (10YR 5/2) gravelly loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine and fine dendritic tubular pores; 15 percent gravel and 5 percent cobbles; finely disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 15 cm thick)
Bk1--28 to 58 cm; very pale brown (10YR 7/3) very gravelly loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; 25 percent gravel and 10 percent cobbles; 25 percent fine, distinct, irregular, soft masses of calcium carbonate, and 80 percent medium, distinct, irregular calcium carbonate nodules on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (15 to 40 cm thick)
Bk2--58 to 79 cm; very pale brown (10YR 8/3) very cobbly sandy loam, very pale brown (10YR 7/3) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; 25 percent gravel and 20 percent cobbles; 50 percent fine, distinct, irregular, soft masses of calcium carbonate, and 80 percent medium, distinct, irregular calcium carbonate nodules on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (20 to 75 cm thick)
BCk--79 to 152 cm; pale yellow (2.5Y 7/4) extremely gravelly fine sandy loam, light yellowish brown (2.5Y 6/4) moist; massive; soft, very friable, nonsticky and nonplastic; 50 percent gravel and 15 percent cobbles; finely disseminated calcium carbonate, and 80 percent medium, distinct, irregular calcium carbonate nodules on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Beaverhead County, Montana; located about 200 feet south and 820 feet east of the northwest corner of sec. 22, T. 6S, R 12W; Polaris topographic quadrangle; UTM 12T, 338259e, 5019137n, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 1 to 4 degrees C.
Depth to calcic horizon - 10 to 30 cm
A horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 2 or 3; dry or moist
Clay content: 18 to 27 percent
Rock fragments: 15 to 30 percent--10 to 30 percent gravel, 0 to 15 percent cobbles
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 6.8 to 7.6
Bw horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 5 or 6 dry; 3 to 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam, sandy loam or fine sandy loam
Clay content: 15 to 27 percent
Rock fragments: 15 to 35 percent--15 to 35 percent gravel, 0 to 15 percent cobbles
Calcium carbonate equivalent: 3 to 10 percent, including coarse fragments less than 20 mm in size
Reaction: pH 7.9 to 8.4
Bk1, Bk2 horizons
Hue: 10YR, 7.5YR or 2.5Y; dry or moist
Value: 6 to 8 dry; 5 to 7 moist
Chroma: 2 or 3; dry or moist
Texture: loam, sandy loam or fine sandy loam
Clay content: 12 to 27 percent
Rock Fragments: 35 to 70 percent--25 to 60 percent gravel, 5 to 25 percent cobbles
Calcium carbonate equivalent: 40 to 60 percent, including coarse fragments less than 20 mm in size
Reaction: pH 8.1 to 8.4
BCk horizon
Hue: 10YR, 7.5YR or 2.5Y; dry or moist
Value: 6 to 8 dry; 4 to 6 moist
Chroma: 2 to 4; dry or moist
Texture: loam, sandy loam or fine sandy loam
Clay content: 10 to 25 percent
Rock Fragments: 35 to 70 percent--25 to 60 percent gravel, 5 to 25 percent cobbles
Calcium carbonate equivalent: 20 to 40 percent, including coarse fragments less than 20 mm in size
Reaction: pH 8.1 to 8.4
COMPETING SERIES:
Foureyes (MT) - do not have an udic moisture subclass
GEOGRAPHIC SETTING:
Landform - hills, mountain slopes, and debris avalanches
Elevation - 1,890 to 2,750 meters
Slope - 8 to 60 percent
Parent material - slope alluvium, colluvium, slide deposits derived from limestone and other calcareous sedimentary rock
Climate - long, cold winters; moist springs; warm summer
Mean annual precipitation - 380 to 600 mm
Mean annual air temperature - 1 to 4 degrees F.
Frost-free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Scudder soils are used mainly for timber production and wildlife habitat. The native overstory vegetation is mainly Douglas-fir, limber pine and Rocky Mountain juniper. The understory vegetation includes Idaho fescue, pinegrass, elk sedge, heartleaf arnica, kinnikinnick, creeping Oregon grape, common juniper, western snowberry, ribes, and other miscellaneous forbs.
DISTRIBUTION AND EXTENT: Scudder soils are of small extent in southwestern Montana. MLRA - 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Horse Prairie-South Valley Area - Part of Beaverhead County, Montana, 2011; proposed in Beaverhead County, Montana, 2008.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 13 cm (A horizon)
Calcic horizon - from 28 to 152 cm (Bk1, Bk2, BCk horizons)
Particle-size control section - from 25 to 100 cm (Bk1, Bk2, part of C horizon)
Scudder soils have a cryic temperature regime, an ustic moisture regime, and an udic moisture subclass.
National Cooperative Soil Survey
U.S.A.