LOCATION HEENLAKE                CA

Established Series
Rev. EWB/JVC/JBF
12/2022

HEENLAKE SERIES

The Heenlake series consists of moderately deep, well drained soils that formed in colluvium and residuum derived from tuff, tuff-breccia, and andesite. Heenlake soils are on mountains. Slopes are 4 to 50 percent. The mean annual precipitation is about 500 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Argixerolls

TYPICAL PEDON: Heenlake very stony loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 20 percent gravel, 10 percent cobbles, and 8 percent stones.

A--0 to 15 cm; grayish brown (10YR 5/2) very stony loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular and interstitial pores; 25 percent gravel, 10 percent cobbles, and 10 percent stones; slightly acid (pH 6.4); clear wavy boundary. (8 to 18 cm thick)

Bt1--15 to 33 cm; dark grayish brown (10YR 4/2) very gravelly clay loam, very dark brown (10YR 2/2) moist; slightly hard, friable, moderately sticky and moderately plastic; moderate fine and medium subangular blocky structure; common very fine through medium roots; common very fine tubular and interstitial pores; many distinct clay films on faces of peds and lining pores; 40 percent gravel, 10 percent cobbles, and 5 percent stones; slightly acid (pH 6.4); clear wavy boundary. (8 to 20 cm thick)

Bt2--33 to 46 cm; dark grayish brown (10YR 4/2) very gravelly clay loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine through coarse roots; common very fine tubular and interstitial pores; many distinct clay films on faces of peds and lining pores; 40 percent gravel and 5 percent cobbles; 5 percent paragravel and 5 percent paracobbles; neutral (pH 6.8); clear wavy boundary. (10 to 20 cm thick)

Bt3--46 to 56 cm; 70 percent brown (7.5YR 5/4) and 30 percent grayish brown (10YR 5/2) very gravelly clay loam, 70 percent dark brown (7.5YR 3/4) and 30 percent very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine through coarse roots; common very fine tubular and interstitial pores; many distinct clay films on faces of peds and lining pores; 40 percent gravel; 10 percent paragravel; neutral (pH 6.8); clear irregular boundary. (10 to 50 cm thick)

Cr--56 to 81 cm; weathered andesitic tuff.

TYPE LOCATION: Alpine County, California; on the Toiyabe National Forest about 0.4 mile south of Heenan Lake; approximately 1,650 feet north and slighty hard1,500 feet west of the southeast corner of section 10, T. 9 N., R. 21 E.; USGS Heenan Lake 7.5 minute topographic quadrangle; latitude 38 degrees 38 minutes 16.2 seconds N and longitude 119 degrees 39 minutes 20.6 seconds W; WGS84 Decimal Degrees 38.6378333 latitude, -119.6557222 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section during late fall, winter, and spring; dry from July through early October for 75 to 90 consecutive days in the four months following the summer solstice; xeric moisture regime that borders on aridic.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 25 to 50 cm; includes the Bt1 and Bt2 horizons.
Depth to base of argillic horizon: 50 to 100 cm.
Depth to bedrock: 50 to 100 cm to a paralithic contact. The paralithic materials below the contact are weathered volcanic rocks such as andesitic tuff.
Sodium fluoride pH: 8.5 to 9.0.

Particle-size control section - Clay content: Averages 25 to 35 percent. Rock fragments: Averages 35 to 60 percent, mainly gravel. Lithology of fragments are volcanic rocks such as tuff, tuff-breccia, and andesite.

A horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 to 4 percent.
Reaction: Slightly acid or neutral.

Bt1 and Bt2 horizons
Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Very gravelly clay loam, very gravelly loam, or very gravelly sandy clay loam.
Clay content: 25 to 30 percent.
Rock fragments: 35 to 60 percent.
Organic matter content: 1 to 3 percent.
Reaction: Slightly acid or neutral.

Bt3 horizon
Hue: 10YR or 7.5YR.
Value: 3 through 5 moist.
Texture: Very gravelly clay loam or very gravelly sandy clay loam.
Clay content: 27 to 35 percent.
Rock fragments: 35 to 60 percent.
Reaction: Slightly acid or neutral.

COMPETING SERIES: These are the Clanalpine, Devaul, Elaero, Glidski, Heechee, Holmes, Horrocks, Hoskin, Howcan, Longday, Pequop, Moreypeak, Suak, Valmar, Vitale, and Wambolt series.

Clanalpine soils typically have mollic epipedons that do not include the Bt horizons and are dominated by cobbles in the particle-size control section. Devaul soils are deep to paralithic contacts. Elaero soils average 12 to 18 percent clay in the particle-size control section, have rock fragments that are granitic rocks, and have paralithic material of weathered granitic rock in the series control section. Glidski, Heechee, Holmes, Howcan, Longday, Pequop, and Wambolt soils are very deep. Horrocks soils are deep to lithic contacts. Hoskin, Suak, Valmar, and Vitale soils are moderately deep to lithic contacts. Moreypeak soils average 18 to 25 percent clay in the particle-size control section.

GEOGRAPHIC SETTING: Heenlake soils are on mountains. They typically occur on footslope and backslope positions. They formed in colluvium and residuum derived from tuff, tuff-breccia, and andesite. Slopes are 4 to 50 percent. Elevations range from 1,650 to 2,655 meters. The climate is subhumid-continental with cold, moist winters and warm, dry summers. The mean annual precipitation is 350 to 600 mm, mean annual temperature is 4 to 7 degrees C., and the frost-free period is 40 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Celeridge, Chenhigh, and Joecut soils. Celeridge and Chenhigh soils have lithic contacts within 50 cm. Joecut soils are very deep and have umbric epipedons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high or very high surface runoff; moderately slow permeability; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Heenlake soils are used for livestock grazing, recreation, watershed, and wildlife habitat. The native vegetation is mainly mountain big sagebrush, antelope bitterbrush, and western needlegrass.

DISTRIBUTION AND EXTENT: Eastern California, on the east side of the Sierra Nevada Range. These soils are moderately extensive. MLRAs 22A and 26.

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

SERIES ESTABLISHED: Alpine County (Toiyabe National Forest Area), California, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 46 cm (A, Bt1, and Bt2 horizons).
Argillic horizon - The zone from 15 to 56 cm (Bt1, Bt2, and Bt3 horizons).
Paralithic contact - The boundary at 56 cm to underlying soft bedrock (Cr layer).
Particle-size control section - The zone from 15 to 56 cm (Bt1, Bt2, and Bt3 horizons).

The revision of October 2003 updated the taxonomic class from Loamy-skeletal, isotic, frigid Typic Argixerolls. The isotic mineralogy class was based solely on the field determined values for sodium fluoride pH. Laboratory data on 15 bar water to clay ratio does not exist to verify the isotic mineralogy class.

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National Cooperative Soil Survey
U.S.A.