LOCATION SNAG                    NV CA

Established Series
Rev. JBF/TM
01/2023

SNAG SERIES

The Snag series consists of very deep, well drained soils that formed in glacial till and glacial debris, volcanic ash and colluvium derived from andesite. Snag soils are on ground moraines on mountains and plateaus. Slopes are 2 to 50 percent. The mean annual precipitation is about 380 mm and the mean annual temperature is about 6.7 degrees C.

TAXONOMIC CLASS: Ashy-skeletal, glassy Vitrandic Argicryolls

TYPICAL PEDON: Snag very stony ashy sandy loam - rangeland. The soil surface is partly covered with 1 percent stones and 2 percent boulders. (Colors are for dry soil unless otherwise noted.)

A1--0 to 10 cm; dark grayish brown (10YR 4/2) very stony ashy sandy loam, black (10YR 2/1) moist; weak coarse prismatic structure parting to moderate medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and medium, common coarse roots; many very fine interstitial and vesicular pores; 20 percent stones, 15 percent cobbles and 10 percent hard volcanic gravel; neutral(pH 6.8); abrupt wavy boundary. (10 to 38 cm thick)

A2--10 to 51 cm; dark grayish brown (10YR 4/2) extremely stony ashy sandy loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine through coarse roots; many very fine tubular pores; 40 percent stones, 10 percent cobbles and 10 percent hard volcanic gravel; neutral (pH 6.7); clear wavy boundary. (23 to 46 cm thick)

A3--51 to 76 cm; dark grayish brown (10YR 4/2) extremely stony ashy loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, common fine, few medium and coarse roots; many very fine and common fine tubular pores; 40 percent stones, 10 percent cobbles and 15 percent hard volcanic gravel; neutral (pH 6.9); clear wavy boundary. (23 to 46 cm thick)

Bt1--76 to 104 cm; brown (7.5YR 5/3) very stony ashy sandy clay loam, dark brown (7.5YR 3/3) moist; moderate coarse subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common very fine, few fine and medium roots; common very fine, few fine and medium tubular pores; common distinct clay films on faces of peds and clay bridges between mineral grains; 15 percent stones, 20 percent cobbles and 15 percent hard volcanic gravel; neutral (pH 7.1); clear wavy boundary. (25 to 51 cm thick)

Bt2--104 to 157 cm; brown (7.5YR 5/2) very cobbly ashy sandy loam, brown (7.5YR 4/3) moist; weak coarse subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine tubular pores; few faint clay films on faces of peds and clay bridges between mineral grains; 5 percent stones, 15 percent cobbles and 30 percent hard volcanic gravel; neutral (pH 7.3).

TYPE LOCATION: Washoe County, Nevada; in the Hays Canyon Range; near Indian Pole Camp; about 1,260 feet north and 220 feet west of the southeast corner section 12, T. 39 N., R. 18 E.; USGS Hays Canyon 7.5 minute topographic quadrangle; 41 degrees 16 minutes 27.9 seconds north latitude and 119 degrees 54 minutes 25.0 seconds west longitude; WGS84 Decimal Degrees 41.2744167 latitude, -119.9069444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist, moist in winter and spring, dry in late summer and fall; completely dry for at least 45 consecutive days between July and October; xeric moisture regime.
MAST - 5.0 to 7.8 degrees C.
MSST - 12.2 to 15.0 degrees C.
Volcanic glass content - 50 to 80 percent in the coarse silt through fine sand fractions.
Reaction - Slightly acid or neutral
Base Saturation - 50 to 75 percent

Control Section:
Clay Content: averages 18 to 24 percent; individual subhorizons range from 16 to 25 percent, decreasing with depth.
Rock Fragments: 50 to 80 percent, dominantly cobbles and stones.
Mollic epipedon thickness: 75 to 114 cm.

A horizon
Hue: 7.5YR or 10YR
Value: 3 or 4 dry, 1, 2 or 3 moist
Chroma: 1 or 2
Structure: Weak or moderate, fine to coarse, subangular blocky or it is weak prismatic parting to subangular blocky.
Consistence: Soft or slightly hard.
Other features: Moist value of 3 does not occur in the Al horizon.

Bt horizon
Hue - 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3
Texture: Ashy sandy clay loam or ashy sandy loam.
Rock fragments: 50 to 80 percent, mainly cobbles and stones. Lithology of the fragments is mostly andesite or andesitic tuff.

COMPETING SERIES: These are the Ashflat, Boulderfan, Cowbell, Fendersflat, Paynepeak, Pyropatti and Tusune series. Ashflat soils have less than 50 percent rock fragments in the control section. Boulderfan and Cowbell soils have a mollic epipedon thickness less than 75 cm. Fendersflat and Tusune soils are moderately deep to a paralithic contact. Paynepeak and Pyropatti soils have paralithic contact at 100 to 152 cm.

GEOGRAPHIC SETTING: Snag soils are on concave ground moraines on mountains and plateaus. They formed in glacial till and glacial debris, volcanic ash and colluvium derived from andesite. Slopes are 2 to 50 percent. Elevations range from 1,700 to 2,445 meters. The mean annual precipitation is 300 to 410 mm, mean annual temperature is 6.1 to 7.2 degrees C., and the frost-free period is 60 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: Snag soils are associated with Brownsbowl, Cavin, Hashwoods and Zorromount soils. Brownsbowl and Cavin soils do not have an argillic horizon. Hashwoods soils are deep to soft bedrock and have fewer than 35 percent rock fragments in the control section. Zorromount soils have a 25 to 38 cm mollic epipedon thickness and do not have an argillic horizon.

DRAINAGE AND PERMEABILITY: Well-drained; slow to medium runoff; moderately rapid permeability.

USE AND VEGETATION: These soils are used to provide livestock grazing and wildlife habitat, and for watershed purposes. The vegetation is dominated by big sagebrush, snowberry, Idaho fescue, mountain brome, western needlegrass, Great Basin wildrye and bluegrasses.

DISTRIBUTION AND EXTENT: Mountainous areas of northeastern California and northwestern Nevada. They are not extensive. MLRA 21, 23.

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

SERIES ESTABLISHED: Lassen County, California, 1971.

REMARKS: Revision 11/4/2003, part of the update to the Surprise Valley-Home Camp Area, CA and NV, moves the type location and changes the classification from loamy-skeletal, mixed, superactive Pachic Haplocryolls to Ashy-skeletal, glassy Vitrandic Argicryolls based on updated soil mapping and to better represent the series as mapped.

Diagnostic horizons and features recognized in the pedon:

Mollic epipedon - The zone from the soil surface to 104 cm (A1, A2, A3 and Bt1 horizons).
Argillic horizon - The zone from 76 to 157 cm (Bt1 and Bt2 horizons).
Particle-size control section - The zone from 76 to 136 (Bt1 and part of the Bt2 horizons).
Vitrandic feature and ashy, glassy texture modifier and mineralogy - 50 to 80 percent glass in all horizons.

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National Cooperative Soil Survey
U.S.A.