LOCATION MILLIGAN IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal over fragmental, mixed, superactive, frigid Typic Haploxerolls
TYPICAL PEDON: Milligan very cobbly loam - on 72 percent southwest facing slope at an elevation of 6,500 feet in rangeland. When described on October 2, 1978, the soil was dry throughout. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 inches; brown (10YR 5/3) very cobbly loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable; many very fine, fine, medium and coarse roots; many very fine interstitial pores; 20 percent gravel and 40 percent cobbles; slightly acid (pH 6.4); gradual wavy boundary. (7 to 15 inches thick)
Bw--8 to 18 inches; yellowish brown (10YR 5/4) extremely cobbly loam, dark yellowish brown (10YR 3/4) moist; weak fine granular structure; soft, very friable; common very fine, fine, medium and coarse roots; many very fine interstitial pores; 45 percent cobbles and 20 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (6 to 13 inches thick)
C--18 to 24 inches; gray (N 5/) displaced fractured limestone bedrock with some voids and some brown (10YR 5/3) loam textured soil between rock fragments; few fine and medium roots, 95 percent rock fragments; abrupt wavy boundary. (5 to 16 inches thick)
2R--24 inches; quartzite.
TYPE LOCATION: Blaine County, Idaho about 5 miles east and 2 miles south of Bellevue; 2,000 feet south and 200 feet west of the northeast corner, sec. 1, T. 1 N., R. 19 E.
Latitude - 43 degrees, 27 minutes, 03 seconds North; Longitude - 114 degrees, 07 minutes, 55 seconds West.
RANGE IN CHARACTERISTICS:
Depth to hard limestone or quartzitic sandstone - 20 to 40 inches
Average annual soil temperature - 42 to 46 degrees F.
Thickness of the mollic epipedon - 7 to 15 inches
Percent clay, textural control section - 8 to 15 percent
A horizon
Color value, dry - 4 or 5
Chroma, moist or dry - 2 to 4
Rock fragments - 35 to 60 percent
Reaction - slightly acid to neutral
Bw horizon
Color value, dry - 4 to 6
Value, moist - 3 or 4
Chroma, moist or dry - 3 or 4
Texture - GRV-L, GRX-L, CBX-L
Rock fragments - 55 to 75 percent
Reaction - neutral to slightly alkaline
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Milligan soils are on metastable talus slopes. Slopes range from 30 to 75 percent. Elevation ranges from 5,200 to 8,500 feet. The soil formed in colluvium from quartzitic sandstone and related rock. The average annual precipitation is 12 to 18 inches, most of which falls as snow and early spring rains. The average annual temperature is about 40 to 44 degrees F. The frost-free season is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dollarhide, Povey, and the Vitale soils. Dollarhide and Povey have average summer temperatures of less than 59 degrees F, and are on north-facing and east-facing slopes. Vitale soils have argillic horizons and occur on south-facing and west-facing slopes.
DRAINAGE AND PERMEABILITY: Well drained, medium to very rapid runoff; moderately rapid permeability to 18 inches and very rapid below this depth.
USE AND VEGETATION: Mainly used for range. Vegetation is mountain big sagebrush, bluebunch wheatgrass, Idaho fescue and antelope bitterbrush.
DISTRIBUTION AND EXTENT: South-central Idaho. These soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Diagnostic horizons and features recognized in this series are:
Mollic epipedon - from the soil surface to 8 inches (A horizon).
Particle-size control section - 10 to 24 inches (Bw and C horizons).
Lithic contact - at about 24 inches (2R horizon).