LOCATION BEARVALLEY CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, magnesic, thermic Pachic Haploxerolls
TYPICAL PEDON: Bearvalley sandy loam, rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 5 inches; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark brown (10YR 2/2) moist; strong very coarse platy structure; soft, very friable, slightly sticky and non plastic; common very fine roots; many very fine interstitial pores; neutral (pH 6.6); abrupt smooth boundary.
A2--5 to 20 inches; dark grayish brown (10YR 4/2) very gravelly sandy loam, very dark brown (10YR 2/2) moist; massive; soft, very friable, slightly sticky and non plastic; few very fine roots; many very fine and fine interstitial pores; neutral (pH 7.2); clear smooth boundary.
A3--20 to 34 inches; brown (10YR 5/3) very gravelly sandy loam, dark brown (10YR 3/3) moist; massive; soft, very friable, slightly sticky and non plastic; many very fine and fine interstitial pores; slightly alkaline (pH 7.5); abrupt smooth boundary.
2C1--34 to 60 inches; brown (10YR 5/3) very gravelly loamy sand, dark brown (10YR 3/3) moist; massive; loose, loose, slightly sticky and non plastic; many very fine and fine interstitial pores; slightly alkaline (pH 7.8); clear smooth boundary.
2C2--60 to 75 inches; brown (10YR 5/3) extremely gravelly loamy sand, dark brown (10YR 3/3) moist; massive; loose, loose, slightly sticky and non plastic; many very fine and fine interstitial pores; Thin discontinuous pendants on underside of fragments; moderately alkaline (pH 8.3).
TYPE LOCATION: Colusa County, California; about 6 1/2 miles southwest of Leesville CA; about 1300 feet east and 200 feet north of the southwest corner of section 33, T. 15 N., R. 5 W., MDB&M; 39 degrees, 6 minutes, 5 seconds north latitude and 122 degrees, 25 minutes, 20 seconds west longitude; USGS Leesville CA topographic quadrangle.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 60 degrees to 63 degrees F. Ca to Mg ratios are 1:3 to 1:6. The 9 to 27 inch SMCS is dry in some or all parts from June 1 to October 31 and moist in all parts from November 1 to May 31.
The A horizon dry colors are 10YR 5/3, 5/2, 4/2; moist colors are 10YR 3/3, 3/2, 2/2. Texture is sandy loam. Clay content ranges from 10 to 18 percent clay. Reaction is neutral to slightly alkaline. Gravel content ranges from 15 to 35 percent in the upper part to 35 to 45 percent in the rest of the horizon.
The 2C horizons colors are 10YR 5/3; moist colors are 10YR 3/3. Texture is loamy sand or coarse sandy loam. Clay content ranges from 5 to 10 percent clay. Reaction is slightly alkaline to moderately alkaline. Gravel content is 40 to 65 percent.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Bearvalley soils are on alluvial fans Elevations are 1300 to 1450 feet. They formed in coarse textured alluvium derived dominantly from serpentine minerals. Slopes are 2 to 5 percent. The climate has relatively hot, dry summers and cool moist winters. Mean annual precipitation ranges from 18 to 20 inches. Mean January temperature is 43 degrees F., mean July temperature is 76 degrees F, mean annual temperature ranges from 58 degrees to 60 degrees F. Frost-free season is 185 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Leesville and Venado(T) soils. Leesville soils have a contrasting particle size family classification (fine-loamy over sandy-skeletal). Venado soils have more than 35 percent clay textural control section.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; negligable runoff; moderately rapid permeability. Flooding has been reduced by erosion of stream beds.
USE AND VEGETATION: Used for livestock grazing. Native vegetation is a sparse stand of annual grasses and forbs.
DISTRIBUTION AND EXTENT: Intermountain valleys of the Coast Range of northern California. The soil is not extensive in MLRA-14.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Colusa County, California, 1996.
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