LOCATION MOUNTAINCITY            NV

Tentative Series
Rev. BKP/PWB/JBF
09/2019

MOUNTAINCITY SERIES

The Mountaincity series consists of shallow well drained soils formed in loess and colluvium derived from granite. Mountaincity soils are on mountains. Slopes are 15 to 50 percent. Mean annual precipitation is about 380 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid Lithic Ultic Argixerolls

TYPICAL PEDON: Mountaincity loam, rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 20 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 10 percent gravel; slightly acid (pH 6.1); clear smooth boundary. (9 to 25 cm thick)

Bt1--20 to 30 cm; brown (10YR 5/3) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine interstitial pores; few faint clay films on faces of peds and lining pores; 20 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (8 to 15 cm thick)

Bt2--30 to 40 cm; brown (10YR 5/3) very gravelly sandy clay loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and moderately plastic; common very fine and fine roots; common very fine interstitial pores; few distinct clay films on faces of peds and lining pores; 40 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (8 to 10 cm thick)

R--40 cm; fractured granite.

TYPE LOCATION: Elko County, Nevada; about 2 miles southeast of Mountain City, NV; 2,200 feet north and 1,800 feet east of the southwest corner of section 27, T. 46 N., R. 53 E; USGS Ungina Wongo 7.5 minute quadrangle; latitude 41 degrees 51 minutes 23.1 seconds N and longitude 116 degrees 0 minutes 31.7 seconds W; WSG84 Decimal Degrees 41.856403 latitude, -116.008795 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and spring, dry in summer and early fall; typic xeric soil moisture regime.
Mean annual soil temperature: 6 to 8 degrees C.
Mollic epipedon: 25 to 50 cm thick.
Base saturation: Averages 50 to 75 percent.
Depth to bedrock: 25 to 50 cm.

Particle-size control section - Clay content: Averages 18 to 27 percent.
Rock fragments: Averages 15 to 35 percent, dominantly fine gravel.

A horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.

Bt1 horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Loam, coarse sandy loam, sandy clay loam or clay loam.
Consistence: Slightly sticky or moderately sticky and slightly plastic or moderately plastic.
Rock fragments: 15 to 35 percent.

Bt2 horizon
Value: 4 through 6 dry, 2 or 3 moist.
Chroma: 2 through 4, dry or moist.
Texture: Loam, coarse sandy loam, or sandy clay loam.
Structure: medium or coarse.
Consistence: Soft or slightly hard, slightly sticky or moderately sticky and slightly plastic or moderately plastic.
Rock fragments: 30 to 60 percent.

Cr horizon (when present)
Rock fragments: 60 to 90 percent dominated by gruss (2-5 mm) with varying amounts of gravel and cobble.

COMPETING SERIES: Currently, there are no competing series.

GEOGRAPHIC SETTING: Mountaincity soils are on mountains and hills occurring on shoulder and backslope positions. These soils formed in loess and colluvium derived from granite. Slopes are 15 to 50 percent. Elevations are 1,700 to 2,440 meters. The climate is cool and semi-arid. Mean annual precipitation is 330 to 400 mm, mean annual temperature is 6 to 7 degrees C, and frost-free period is 70 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Watchabob soils. Watchabob soils are moderately deep and have a mollic epipedon that averages 50 cm or greater.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high runoff; moderate saturated hydraulic conductivity.

USE AND VEGETATION: Mountaincity soils are used for livestock grazing and wildlife habitat. The vegetation is principally stunted mountain big sagebrush, bluebunch wheatgrass, Thurbers needlegrass, Idaho fescue, rabbitbrush, and lupine.

DISTRIBUTION AND EXTENT: Northeastern Nevada. MLRA 25. These soils are of limited extent.

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

SERIES PROPOSED: Duck Valley Indian Reservation, Idaho and Nevada.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 40 cm (A, Bt1 and Bt2 horizons).
Argillic horizon - The zone from about 20 to 40 cm (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 40 cm (R layer).
Particle-size control section - The zone from 20 to 40 cm (Bt1 and Bt2 horizons).

Remarks: This soil was previously identified as Bearskin variant in the Duck Valley Indian, Nevada and Idaho soil survey. Additional acres of this soil is known to occur on the Humboldt National Forest, Nevada north part soil survey. For this reason a new series is proposed.

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National Cooperative Soil Survey
U.S.A.