LOCATION TENMILE IDEstablished Series
The Tenmile series consists of very deep, well drained soils on
dissected alluvial terraces. They formed in coarse mixed alluvium.
Permeability is slow. Slopes are 0 to 65 percent. The average annual
precipitation is about 12 inches, and the average annual air
temperature is about 50 degrees F.
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Xeric Haplargids
Haplargids.
TYPICAL PEDON: Tenmile very gravelly loam - rangeland. (Colors are
for dry soil unless otherwise noted.)
A--0 to 10 inches; pale brown (10YR 6/3) very gravelly loam, dark
brown (10YR 3/3) moist; weak thin platy structure; slightly hard,
friable, slightly sticky and slightly plastic; many fine and few medium
roots; many fine and medium tubular pores; about 35 percent pebbles;
mildly alkaline (pH 7.7); gradual smooth boundary. (8 to 10 inches
thick)
Bt1--10 to 14 inches; light yellowish brown (10YR 6/4) very
gravelly clay loam, dark brown (10YR 3/3) moist; yellowish brown (10YR
5/4) coatings on faces of peds; strong medium subangular blocky
structure; hard, friable, sticky and plastic; common fine roots; many
very fine and fine tubular pores; many thick clay films on faces of
peds and in pores; about 32 percent pebbles and 5 percent cobbles;
mildly alkaline (pH 7.7); clear smooth boundary. (3 to 6 inches thick)
Bt2--14 to 31 inches; light yellowish brown (10YR 6/4) very
gravelly clay loam, dark brown (10YR 3/3) moist; yellowish brown (10YR
5/4) coatings on faces of peds; strong medium subangular blocky
structure; very hard, very firm, sticky and plastic; few fine roots;
common very fine and fine tubular pores; continuous thick clay films on
faces of peds; about 38 percent pebbles and 10 percent cobbles; mildly
alkaline (pH 7.7); clear smooth boundary. (12 to 17 inches thick)
Bt3--31 to 37 inches; light yellowish brown (10YR 6/4) very
gravelly sandy clay, dark yellowish brown (10YR 4/4) moist; strong
medium subangular blocky structure; hard, firm, sticky and plastic; few
fine roots; common very fine and fine tubular pores; many moderately
thick clay films on faces of peds; about 40 percent pebbles and 12
percent cobbles; mildly alkaline (pH 7.7); gradual wavy boundary. (4
to 7 inches thick)
BC--37 to 49 inches; brownish yellow (10YR 6/6) extremely gravelly
sandy clay loam, dark yellowish brown (10YR 4/6) moist; weak fine
subangular blocky structure; slightly hard, friable, slightly sticky
and slightly plastic; few very fine tubular pores; about 50 percent
pebbles and 10 percent cobbles; moderately alkaline (pH 7.9); gradual
smooth boundary. (12 to 30 inches thick)
2C--49 to 60 inches; variegated extremely gravelly loamy coarse
sand; single grained; loose; about 50 percent pebbles and 15 percent
cobbles; slightly calcareous; moderately alkaline (pH 8.0).
TYPE LOCATION: Ada County, Idaho; about 3-1/2 miles southwest of the
Boise Municipal Airport; approximately 900 feet north and 150 feet east
of the SW corner of section 7, T.2N., R.2E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 50 to 56 degrees F
A horizon
Value- 5 or 6 dry, 2 through 4 moist
Chroma- 2 or 3
Bt horizon
Hue- 7.5YR or 10YR
Value- 4 through 6 dry, 3 through 5 moist
Chroma- 3 through 6
Texture - GRV-CL, GRV-SC, GRX-SC, GRX-C
Clay content - 35 to 55 percent
Pebble content - 35 to 50 percent
Cobble and stone content - 10 to 15 percent
C horizon
Color- variegated
Texture - GRV-SCL, GRV-SL, GRX-LCOS, GRX-S
Rock fragments - 60 to 85 percent
COMPETING SERIES: These are the Berning, Havingdon, Pula, Pulcan,
Surgem, and Zephan series. Berning soils have sola that range in
thickness from 40 to 60 inches or more and are neutral or slightly acid
throughout. Havingdon and Surgem soils have a lithic contact within a
depth of 40 inches. Pula soils have average annual temperatures of 47
to 51 degrees F. Pulcan soils have a paralithic between 28 and 40
inches.
GEOGRAPHIC SETTING: Tenmile soils are on dissected alluvial terraces.
Elevation ranges from 2,700 to 4,500 feet. Slopes are 0 to 65
percent. The soils formed in coarse mixed alluvium with a slight
influence of loess. Average annual precipitation ranges from 10 to 14
inches. Average January temperature is about 27 degrees F, average
July temperature is about 71 degrees F, and the average annual
temperature is 49 to 55 degrees F. Frost-free period is 100 to 160
days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ada, Brent, Chilcott,
Day, Ladd, Lankbush, Lanktree, and Searles soils. Ada, Ladd, and
Searles soils have a mollic epipedon. Brent, Chilcott, Day, Lankbush,
and Lanktree soils have less than 35 percent coarse fragments in the
textural control section. Chilcott and Day soils are on gently sloping
terrace tops. Ladd and Searles soils are at higher elevations. Ada,
Brent, Lankbush, and Lanktree soils are on landscape positions similar
to Tenmile soils.
DRAINAGE AND PERMEABILITY: Well drained; slow through very rapid
runoff; slow permeability.
USE AND VEGETATION: The soils are used dominantly for rangeland.
Vegetation in the potential natural plant community is mainly Wyoming
big sagebrush, antelope bitterbrush, bluebunch wheatgrass, and Sandberg
bluegrass.
DISTRIBUTION AND EXTENT: Southwestern Idaho. These soils are
moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Ada County, Idaho, 1977.
National Cooperative Soil Survey