LOCATION MAYHILL ID

Tentative Series
IRD. KLM/TDT
06/2011

MAYHILL SERIES

The Mayhill series consists of very deep, well drained soils that formed in colluvium and residuum from sandstone. Mayhill soils are on mountains. Slope ranges from 12 to 60 percent. The mean annual precipitation is about 500 mm and the mean annual temperature is about 2.2 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Palecryolls

TYPICAL PEDON: Mayhill loam on a north-facing, 38 percent slope, in a Douglas-fir forest at an elevation of 1981 meters; (Colors are for dry soil unless otherwise stated.)

Oi -- 0 to 2 cm; slightly decomposed litter of needles, leaves and grasses. (0 to 3 cm thick)

A1 -- 2 to 12 cm; very dark grayish brown (10YR 3/2) loam, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots; many very fine and common fine tubular pores; 10 percent gravel; moderately acid (pH 5.8); abrupt wavy boundary.

A2 -- 12 to 40 cm; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable, slightly sticky and nonplastic; common very fine and fine, and few medium, coarse, and very coarse roots; many very fine and fine tubular pores; 20 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (Combined thickness of the A horizon is 25 to 38 cm)

E1 -- 40 to 60 cm; pale brown (10YR 6/3) gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine and fine and few medium and coarse roots; many fine and few very fine and medium tubular pores; 25 percent gravel and 5 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (18 to 41 cm thick)

E2 -- 60 to 91 cm; light yellowish brown (10YR 6/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few very fine, fine and medium roots; common very fine and fine tubular pores; 30 percent gravel and 10 percent cobbles; neutral (pH 6.6); clear smooth boundary. (25 to 50 cm thick)

EBt -- 91 to 124 cm; light yellowish brown (10YR 6/4) very gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; few very fine and common fine roots; many very fine and few fine and medium tubular pores; 10 percent discontinuous distinct clay films on vertical faces of peds and around rock fragments; 35 percent gravel and 10 percent cobbles; neutral (pH 6.6); abrupt wavy boundary. (0 to 50 cm thick)

2Bt -- 124 to 154 cm; brown (7.5YR 5/4) very gravelly clay loam, brown (7.5YR 4/4) moist; strong fine and medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few fine and medium roots; common very fine, fine and medium tubular pores; 90 percent continuous prominent clay films on vertical faces of peds, around rock fragments, and lining pores; 35 percent gravel and 10 percent cobbles; slightly acid (pH 6.4).

TYPE LOCATION: Caribou County, Idaho; about 8.4 kilometers northwest of Henry; 274 meters north and 533 meters east of the southwest corner of section 17, T. 5 S., R. 42 E.; Henry, USGS topographic quadrangle; latitude 42 degrees 58 minutes 44.7 seconds north and longitude 111 degrees 33 minutes 48.5 seconds west, NAD83.

RANGE IN CHARACTERISTICS:
Mollic epipedon thickness: 25 to 38 cm
Depth to the argillic horizon: 68 to 94 cm
Soil moisture regime: udic
Mean annual soil temperature: 2 to 5 degrees C
Mean summer soil temperature: 5 to 8 degrees C when O horizon present and 12 to 15 degrees C when the O horizon is absent

Particle-size control section:
Clay content: averages 20 to 35 percent
Rock fragments: 35 to 60 percent gravel and cobbles

O horizon is absent in some pedons

A horizons
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry or moist
Rock fragments: 0 to 20 percent gravel
Reaction: moderately acid or slightly acid

E horizons
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 3 or 4 dry, 3 to 6 moist
Texture: L or SL with 15 to 50 percent total rock fragments; 15 to 40 percent gravel and 0 to 10 percent cobbles
Reaction: slightly acid or neutral

EBt horizon (when present)
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 4 or 5 dry or moist
Clay content: 20 to 28 percent
Texture: SCL or L with 35 to 60 percent total rock fragments; 35 to 55 percent gravel and 0 to 15 percent cobbles.
Reaction: slightly acid or neutral

2Bt Horizons
Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 to 6 dry or moist
Clay content: 25 to 35 percent
Texture: CL or SCL with 35 to 60 percent total rock fragments; 35 to 50 percent gravel and 0 to 15 percent cobbles.
Reaction: slightly acid or neutral

COMPETING SERIES: These are the Goldmine, Lucky Star and Nordic series. Goldmine and Lucky Star series have an albic horizon. In addition, Goldmine soils have glossic horizon and the rock fragments are dominated by channers and flagstones. The Nordic series needs significant upate for adequate series seperation.

GEOGRAPHIC SETTING:
Landscape: Mountains
Landform: Mountain slopes
Elevation: 1,896 to 2,349 meters
Slope: 12 to 60 percent
Parent material: mixed colluvium and residuum from sandstone
Mean annual air temperature: 0.6 to 3.3 degrees C.
Mean annual precipitation: 450 to 550 mm
Frost free period: 30 to 65 days

GEOGRAPHICALLY ASSOCIATED SOILS: These soils are the Agassiz, Dranburn, Dranyon, and Zeebar series.
Agassiz soils are on ridges, have a loamy-skeletal particle-size control section and are shallow to bedrock.
Dranburn and Dranyon soils are on adjacent mountain slopes, have a fine-loamy particle-size control section and an argillic horizon that occurs higher in the soil profile. Zeebar soils are on similar landscape positions, with a depth to the argillic horizon from 15 to 33 cm.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: Well
Runoff: Medium to rapid
Saturated hydraulic conductivity: moderately low

USE AND VEGETATION:
Major uses: Timber production, livestock grazing, and wildlife habitat.
Vegetation: Rocky Mountain Douglas-fir, quaking aspen, snowberry, serviceberry and mountain brome.

DISTRIBUTION AND EXTENT: Southeastern Idaho; MLRA 13 and 47. The soils are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES PROPOSED: Caribou County Area, Idaho, 2009.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
All depths are measured from the top for the first mineral horizon
Mollic epipedon: from a depth of 2 to 40 cm
The E horizon (s) do not meet the color requirement for albic materials
Argillic horizon: from a depth of 91 to 154 cm
Particle-size control section: from a depth of 91 to 141 cm
Soil temperature regime: cryic
Soil moisture regime: udic

National Cooperative Soil Survey
U.S.A.