LOCATION MIDDLEHILL              ID

Established Series
FRK/GHL
09/2019

MIDDLEHILL SERIES

The Middlehill series consists of moderately deep, well drained, moderately permeable soils that are formed in alluvium and residuum of mica schist and quartzite. They are on mountainsides. Slopes are 20 to 55 percent. The average annual precipitation is about 410 mm and the annual air temperature is about 4.4 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Haplocryolls

TYPICAL PEDON: Middlehill extremely stony sandy loam, rangeland, on a37 percent south westerly slope, 8,200 feet elevation. Class 4 stones on the surface. When described on July 2, 1986 the soil was moist above 41 cm and dry below. (Colors are for air dry soil unless otherwise noted.)

A--0 8 cm; brown (10YR 5/3) extremely stony sandy loam, dark brown (10YR 3/3) moist; strong fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; 35 percent stones, 15 percent cobbles, and 30 percent gravel; neutral (pH 7.2); abrupt smooth boundary.

AB--8 to 23 cm; brown (10YR 5/3) extremely stony loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; 40 percent stones, 10 percent cobbles, and 30 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (Combined thickness of the A horizons is 18 to 36 cm)

Bw--23 to 41 cm; yellowish brown (10YR 5/4) extremely cobbly sandy loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine and few fine roots; many very fine tubular pores; 15 percent stones, 30 percent cobbles, 25 percent gravel; slightly alkaline (pH 7.6); abrupt wavy boundary. (18 to 56 cm thick)

Bk--41 to 61 cm; yellowish brown (10YR 5/4) extremely stony loamy coarse sand, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine tubular pores; 60 percent stones, 15 percent cobbles, 10 percent gravel; slightly effervescent matrix, underside of rock fragments 50 to 75 percent coated with strongly effervescent carbonates; moderately alkaline (pH 8.0); abrupt wavy boundary. (10 to 28 cm thick)

R--61 cm; unweathered, slightly fractured, quartzite with many strongly effervescent carbonate coatings.

TYPE LOCATION: Cassia County, Idaho; about 9 miles south of Oakley, Idaho, 2550 feet north, 1650 feet west of the southeast corner of section 25, T. 15 S., R. 22 E.; USGS Lyman Pass 7.5 minute topographic quadrangle; latitude 42 degrees 05 minutes 26 seconds N and longitude 113 degrees 49 minutes 13 seconds W; WGS84 Decimal Degrees 42.0905556 latitude, -113.8202778 longitude.

RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 18 to 38 cm.
Depth to bedrock - 50 to 100 cm.
Depth to secondary carbonates - 28 to 97 cm.
Average annual soil temperature - 4.4 to 6.7 degrees C.
The average annual precipitation ranges from 360 to 510 mm,
Typic xeric moisture regime.

A horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3
Reaction - neutral to mildly alkaline

Bw horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 through 4
Texture - CBV-SL, CBV-COSL, CBX-SL, STV-L, STX-SL, GRX-SL, GRV-L
Clay content - 5 to 18 percent
Rock fragments greater than 8 cm - 25 to 45 percent
Gravel - 25 to 35 percent
Reaction - neutral to mildly alkaline

Ck horizon
Value - 5 through 7 dry, 4 through 6 moist
Chroma - 3 or 4
Texture - STX-LCOS, STX-SL, CBV-COSL, CBV-SL, GRX-SL
Rock fragments greater than 8 cm - 30 to 75 percent
Gravel - 10 to 35 percent

COMPETING SERIES: These are the Antrobus, Brickel, Broad Canyon, Decram, Fairydell, Farlow, Foxmont, Grafen, Greyback, Handran, Kamack, Klug, Lag, Maurice, Midelight, Midfork, Parachute, Rockabin, Sebud, Silvercliff, Sup, Supervisor, Thornburgh, Tiban, Tineman, and Wareagle series. Brickel soils have significant amounts of volcanic ash in the upper part of the profile. Antrobus, Broad Canyon, Greyback, Handran, Klug, Lag, Midfork, Sup, Tineman, and Wareagle soils are very deep. Decram, Midelight, Parachute, Sebud, and Tiban soils have greater than 18 percent clay in the control section. Fairydell, Farlow, Kamack, Maurice, Silvercliff, and Thornburgh soils are deep. Foxmont and Grafen soils have Cr horizons at 50 to 100 cm and lack secondary carbonates. Rockabin soils have very gravelly textures and 5 percent or less stones in the profile. Supervisor soils have O horizons and lack secondary carbonates in the profile.

GEOGRAPHIC SETTING: Middlehill soils are on moderately steep to steep mountainsides. Slopes range from 20 to 55 percent. Elevation ranges from 6,700 to 8,400 feet. The soil formed in alluvium and residuum of mica schist and quartzite with some loess influence. The average annual precipitation ranges from 360 to 510 mm, the average annual air temperature is about 38 to 42 degrees F., the frost free season is less than 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Birchcreek, Chen, Hades, Povey, Vipont, and Yeates Hollow series. Birchcreek, Chen, Hades, Vipont, and Yeates Hollow soils have argillic horizons and are frigid. Povey soils are Pachic. Birchcreek and Vipont soils are moderately deep. Chen soils are shallow. Hades and Povey soils are very deep and deep respectively. Birchcreek, Chen, Hades, Vipont, and Yeates Hollow soils are on mountainsides at lower elevations than Middlehill. Povey soils are on slightly concave positions on mountainsides and steep north-facing slopes.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Rapid runoff. Moderatel saturated hydraulic conductivity in the upper part and moderately rapid below.

USE AND VEGETATION: Middlehill soils are used for rangeland and wildlife habitat. The native vegetation is low sagebrush, bluebunch wheatgrass, and Sandberg bluegrass.

DISTRIBUTION AND EXTENT: High mountainous areas of south central Idaho. The soils of this series are inextensive. MLRA 13.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Cassia County, Idaho, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are: Mollic epipedon - The zone from the soil surface to 23 cm (A and AB horizons).
Cambic horizon - The zone from 23 to 41 cm (Bw horizon).
Secondary carbonates - The zone from 41 to 61 cm (Bk horizon).
Lithic contact - The boundary at 61 cm (R contact).

Particle-size control section - The zone from 25 cm to the lithic contact at 61 cm (Part of the Bw and Bk horizons).

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National Cooperative Soil Survey
U.S.A.