LOCATION HARAHILL IDEstablished Series
The Harahill series consists of moderately deep, well drained soils on
basalt plains and foothills. They formed in material weathered from
basalt and rhyolite. Permeability is moderate. Slopes are 0 to 30
percent. The average annual precipitation is about 14 inches and the
average annual air temperature is about 42 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Ultic Haploxerolls
TYPICAL PEDON: Harahill loam - rangeland. (Colors are for dry soil
unless otherwise noted.)
A1--0 to 4 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3)
moist; moderate very thin platy structure that parts to moderate very
fine granular; soft, very friable, slightly sticky and slightly
plastic; many very fine and fine roots; many very fine interstitial
pores; 10 percent pebbles; moderately acid (pH 6.0); clear smooth
boundary. (3 to 5 inches thick)
A2--4 to 12 inches; brown (7.5YR 4/2) loam, dark reddish brown (5YR
3/3) moist; moderate medium subangular blocky structure; hard, friable,
slightly sticky and slightly plastic; many very fine and fine, few
medium and coarse roots; many very fine and fine tubular pores; 5
percent pebbles; slightly acid (pH 6.2); clear wavy boundary. (6 to 10
inches thick)
Bw--12 to 20 inches; brown (7.5YR 4/2) loam, dark reddish brown
(5YR 3/3) moist; moderate medium prismatic structure that parts to
moderate fine and medium subangular blocky; hard, firm, sticky and
plastic; common very fine and fine, few medium and coarse roots; many
fine tubular pores; few thin clay films on faces of peds and in pores;
10 to 15 percent pebbles; slightly acid (pH 6.3); clear wavy boundary.
(7 to 13 inches thick)
BC--20 to 26 inches; brown (7.5YR 4/2) very gravelly loam, dark
reddish brown (5YR 3/3) moist; moderate fine subangular blocky
structure; slightly hard, friable, slightly sticky and slightly
plastic; common very fine and fine roots; common fine tubular pores;
few thin clay films on faces of peds and in pores; 15 percent cobbles
and 45 percent pebbles; slightly acid (pH 6.3); gradual irregular
boundary. (4 to 8 inches thick)
R--26 inches; basalt with decomposition in the upper 3 inches.
TYPE LOCATION: Camas County, Idaho; about 1 mile west and 2 miles
north of Hill City, at a point 250 feet west and 1,300 feet north of
the southest corner of section 18, T. 1 S., R. 12 E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 41 to 47 degrees F
Depth to bedrock - 24 to 40 inches
Mollic epipedon thickness - 20 to 28 inches
Reaction in profile - slightly or moderately acid
Base saturation - 50 to 75 percent in some part above 30 inches
Rock fragments in control section - 5 to 25 percent pebbles, cobbles,
and stones
A horizon
Hue- 5YR through 10YR
Value- 4 or 5 dry, 2 or 3 moist
Chroma- 2 or 3
Bw horizon
Hue- 5YR or 7.5YR
Value- 4 or 5 dry, 3 or 4 moist
Chroma- 2 through 6
Texture - SIL, L, CL, ST-SIL, ST-L, ST-CL, CB-L
Clay content - 20 to 30 percent
COMPETING SERIES: These are the Childs, Congle(T), Kahler, and M?Garr
series. Childs soils are deeper than 60 inches to bedrock. Kahler
soils are 40 to 60 inches deep to bedrock. M?Garr soils have an 0
horizon. Congle soils are greater than 40 inches to bedrock.
GEOGRAPHIC SETTING: Harahill soils are on basalt plains and foothills
and have 0 to 30 percent slopes. Elevations are 4,800 to 6,000 feet.
The soils formed in residuum and alluvium weathered from basalt or
rhyolite. The average annual precipitation ranges from 12 to 16
inches. Average January temperature is 15 degrees F, the average July
temperature is 66 degrees F, and the average annual air temperature is
39 to 44 degrees F. The frost-free season is about 60 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Laurentzen and
Polecreek soils. Laurentzen soils are more than 40 inches deep to
bedrock. Polecreek soils are 10 to 20 inches deep to bedrock and have
a clay B2t horizon. These soils are on landscape positions similar to
the Harahill soil.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff;
moderate permeability.
USE AND VEGETATION: The soils are used for rangeland. Vegetation in
the potential natural plant community is mainly bluebunch wheatgrass,
Idaho fescue, mountain big sagebrush, lupine, and arrowleaf balsam
root.
DISTRIBUTION AND EXTENT: Basalt plains at high elevations in
south-central and southwestern Idaho. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Camas County, Idaho, 1977.
REMARKS: Diagnostic horizons and other features recognized in this
pedon are:
Mollic epipedon - the zone from 0 to 26 inches.
Particle-size control section - the zone from 10 to 26 inches.
Lithic contact at a depth of 26 inches.
National Cooperative Soil Survey