LOCATION WINNEMUCCA         UT+CO
Established Series
Rev. RSJ/MJD
02/1999

WINNEMUCCA SERIES


The Winnemucca series consists of very deep, well drained, slowly permeable soils. They formed in alluvium and colluvium derived from intermediate volcanic materials on mountain meadows, mountaintops, and mountain slopes. Slopes range from 1 to 60 percent. The mean annual air temperature is 36 degrees F, and the mean annual precipitation is 28 inches.

TAXONOMIC CLASS: Clayey-skeletal, smectitic Pachic Argicryolls

TYPICAL PEDON: Winnemucca gravelly silt loam - rangeland. (Colors are for air-dry soil unless otherwise stated.)

A1--0 to 5 inches; very dark grayish brown (10YR 3/2) gravelly silt loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many fine roots; many very fine interstitial pores; 15 percent gravel; slightly acid (pH 6.5); gradual smooth boundary. (4 to 6 inches thick)

A2--5 to 11 inches; very dark grayish brown (10YR 3/2) gravelly silt loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure parting to moderate fine and medium granular; soft, friable, slightly sticky and slightly plastic; common fine roots; common fine interstitial pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.5); clear wavy boundary. (6 to 10 inches thick)

BA--11 to 18 inches; brown (7.5YR 4/2) very cobbly loam, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common fine interstitial and tubular pores; few thin clay films on faces of peds; 25 percent cobbles, 5 percent stones and 5 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (5 to 8 inches thick)

Bt1--18 to 24 inches; reddish brown (5YR 5/4) very cobbly clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, firm, sticky and plastic; common very fine roots; few coarse interstitial pores; few thin clay films on faces of peds; 50 percent cobbles; 5 percent gravel and 5 percent stones; slightly acid (pH 6.5); gradual wavy boundary. (5 to 10 inches thick)

Bt2--24 to 28; reddish brown (5YR 5/4) extremely cobbly clay loam, reddish brown (5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; few very fine roots; few coarse interstitial pores; few thin clay films in pores; 55 percent cobbles, 10 percent stones and 5 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (3 to 8 inches thick)

C--28 to 60 inches; light reddish brown (5YR 6/4) extremely stony loam, reddish brown (5YR 5/4) moist; massive; hard, firm, slightly sticky and nonplastic; few very fine roots; few coarse interstitial pores; 50 percent stones and 20 percent cobbles; neutral (pH 7.0).

TYPE LOCATION: Garfield County, Utah; Winnemucca Flats; northwest corner, sec. 5, T. 32 S., R. 3 W.

RANGE IN CHARACTERISTICS: The mollic epipedon is 16 to 30 inches thick. These soils have a mean annual soil temperature of about 36 to 40 degrees F, and a mean summer soil temperature at depth of 20 inches is about 50 to 55 degrees F.

The A and BA horizons have hue of 7.5YR or 10YR, value of 3 to 5 dry, 2 or 3 moist and chroma of 2 to 4.

The Bt horizon has hue of 5YR or 7.5YR, value of 4 to 6 dry, 3 or 4 moist and chroma of 2 to 6. It is very or extremely gravelly to cobbly or very cobbly clay loam to clay, but averages about 35 to 42 percent clay and 35 to 70 percent rock fragments.

The C or 2C horizons have hue of 5YR or 7.5YR, value of 5 or 6 dry, 4 or 5 moist and chroma of 3 to 6. It is very gravelly sandy loam to very gravelly, very cobbly and extremely stony loam, clay loam, clay or extremely cobbly clay.

COMPETING SERIES: These are the Castino (UT), Doughspon T(CO), Friedman (ID), Hamtah (NV), Urwill (NV) series. Hamtah and Urwill soils have sola more than 48 inches thick. Castino soils are 20 to 40 inches deep to bedrock. Doughspon soils have a lithic contact at 40 to 60 inches. Friedman soils are 42 to 60 inches to the base of the argillic horizon.

GEOGRAPHIC SETTING: Winnemucca soils are in moderately sloping to steep mountain meadows, mountaintops, and mountain slopes at elevations of 7,600 to 10,500 feet. They formed in alluvium and colluvium from intermediate volcanic, glacial basaltic materials, and interbedded sandstone and shale. Slope gradients are 1 to 60 percent. The average annual precipitation is 16 to 40 inches and the freeze-free period ranges from 40 to 75 days. The mean annual temperature is 34 to 40 degrees F, and the mean summer temperature is 50 to 55 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Behanin and Callings soils. Behanin soils have loamy Bt horizons with less than 35 percent clay. Callings soils have an E horizon that tongues into the argillic horizon.

DRAINAGE AND PERMEABILITY: Moderately well to well drained; medium runoff; slow permeability.

USE AND VEGETATION: This soils is used for rangeland and wildlife habitat. Native vegetation is subalpine needleandthread grass, slender wheatgrass, mountain bromegrass, squirreltail, sedges and scattered big sagebrush.

DISTRIBUTION AND EXTENT: These soils are on the Sevier Plateau in the south central part of Utah and in western Colorado. They are moderately extensive. MLRA 47 and 48A

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

SERIES ESTABLISHED: Garfield County (Paunsaugunt Soil Survey Area), Utah, 1969.

REMARKS: Diagnostic horizon and features recognized in this pedon are:

Mollic epipedon -The zone from the surface of the soil to 18 inches (A1, A2, BA horizons)

Argillic horizon -The zone from 18 to 28 inches (Bt1, Bt2 horizons)

Pachic feature -A mollic epipedon thicker than 16 inches.


National Cooperative Soil Survey
U.S.A.