LOCATION HUNGRYHILL              MT

Established Series
JMS/EMM/RJS
02/2012

HUNGRYHILL SERIES

The Hungryhill series consists of moderately deep, well drained soils that formed in colluvium and slope alluvium from rhyolite and other moderately fine-grained igneous rocks. These soils are on mountains, hills and ridges of structural benches. Slopes are 2 to 60 percent. Mean annual precipitation is about 432 millimeters and mean annual air temperature is about 3 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Argicryolls

TYPICAL PEDON: Hungryhill gravelly loam, in rangeland on an 18 percent slope at 1,750 meters elevation (colors are for dry soil unless otherwise indicated).

A--0 to 18 cm; very dark grayish brown (10YR 3/2) gravelly loam, black (10YR 2/1) moist; weak fine granular structure; very friable, slightly hard, slightly sticky and moderately plastic; many very fine and fine roots; many fine tubular pores; 20 percent gravel, 5 percent cobbles, 3 percent stones; slightly acid (pH 6.4); clear wavy boundary. (18 to 40 cm thick)

Bt--18 to 43 cm; brown (10YR 5/3) very gravelly clay loam, brown (10YR 4/3) moist; weak medium prismatic structure; friable, hard, moderately sticky and moderately plastic; many fine roots; many fine irregular and tubular pores; common distinct clay films on ped faces; 40 percent gravel, 20 percent cobbles; neutral (pH 6.6); gradual wavy boundary. (18 to 28 cm thick)

BC--43 to 66 cm; pale brown (10YR 6/3) very gravelly sandy clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; friable, hard, moderately sticky and moderately plastic; common very fine roots; common fine irregular pores; 45 percent gravel; neutral (pH 6.8); abrupt irregular boundary.

R--66 cm; indurated rhyolitic tuff.

TYPE LOCATION: Opportunity topographic quadrangle, Silver Bow County, Montana; 670 meters south and 10 meters west of the NE corner of section 15, T. 3 N., R. 10 W. UTM Zone 12: 359126e, 5097154n, NAD 83.

RANGE IN CHARACTERISTICS:
Soil temperature - 2 to 6 degrees C
Moisture control section - 10 cm to the top of the lithic contact
Thickness of the mollic epipedon - 18 to 40 cm
Depth to lithic contact 50 to 100 cm
Surface fragments - 0 to 3 percent stones

A horizon
Hue: 10YR or 2.5Y
Value: 3 to 5 dry; 2 to 3 moist
Chroma: 2 or 3, dry or moist
Texture: loam, fine sandy loam or loamy fine sand
Clay content: 10 to 27 percent
Rock fragments: 10 to 60 percent--10 to 45 percent gravel, 0 to 15 percent cobbles, 0 to 5 percent stones
Reaction: pH 5.2 to 6.8

Bt horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 2 or 3 dry, 3 or 4 moist
Texture: sandy clay loam, clay loam or loam
Clay content: 16 to 32 percent
Rock fragments: 35 to 60 percent--30 to 50 percent gravel, 5 to 20 percent cobbles, 0 to 5 percent stones
Reaction: pH 5.8 to 7.6

BC horizon
Hue: 10YR or 2.5Y
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: sandy clay loam, sandy loam or loam
Clay content: 8 to 22 percent
Rock fragments: 40 to 65 percent--35 to 60 percent gravel; 5 to 15 percent cobbles
Reaction: pH 5.8 to 7.6

COMPETING SERIES:
Blaine (MT) - has horizons of secondary carbonate accumulation.
Bowen (CO) - has horizons of secondary carbonate accumulation.
Fingerrock (CO) - is very deep.
Fornor (WY) - is very deep.
Fourmile (CO) - is very deep.
Geertsen (UT) - is deep.
Hodden (CO) - is very deep.
Hoodle (UT) - is very deep.
Lagarita (CO) - is very deep.
Libeg (MT) - is very deep.
Nathale (WY) - has horizons of secondary carbonate accumulation.
Nathrop (CO) - has horizons of secondary carbonate accumulation.
Norriston (CO) - is very deep.
Quander (CO) - is deep or very deep.
Ratiopeak (MT) - is very deep.
Spanpeak (MT) - is very deep.
Woodhall (CO) - rock fragments are dominantly stones throughout.

GEOGRAPHIC SETTING:
Landform - mountains, mountaintop ridges and hills
Elevation - 1,550 to 2,290 meters
Slope - 2 to 60 percent
Parent material - colluvium or slope alluvium derived from rhyolite, rhyodacite, or rhyolitic tuff
Climate - long, cold winters; cold, moist springs; short, cool summers
Mean annual precipitation - 305 to 559 millimeters, much of which falls as snow and as spring rain
Mean annual air temperature - 1 to 5 degrees centigrade
Frost-free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bullrey, Euell and Eastridge soils which occur on similar landforms. Bullrey soils have a mollic epipedon that is 50 to 75 cm thick. Euell soils are deep to a lithic contact. Eastridge soils are very deep.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: Hungryhill soils are used mainly for rangeland. Potential native vegetation is bluebunch wheatgrass, Idaho fescue with some areas of widely scattered Douglas fir and Rocky Mountain juniper.

DISTRIBUTION AND EXTENT: Hungryhill soils are of small extent in the intermontane basins of central Montana. MLRA 43B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.

SERIES ESTABLISHED: Silver Bow County, Montana, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 18 cm (A horizon)
Particle-size control section - from 18 to 43 cm (Bt horizon)
Hungryhill soils have a cryic temperature regime and an ustic moisture regime.

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National Cooperative Soil Survey
U.S.A.