LOCATION SLEEPER                 CA

Established Series
HVB/WDB/NHS/DJE/SBS
01/2023

SLEEPER SERIES

The Sleeper Series consists of deep, well drained soils that formed in material weathered from sandstone, shale and siltstone. Sleeper soils are on hills. Slopes are 5 to 50 percent. The mean annual precipitation is about 32 inches, and the mean annual temperature is about 57 degrees F.

TAXONOMIC CLASS: Fine, smectitic, thermic Mollic Haploxeralfs

TYPICAL PEDON: Sleeper loam - on a northwest facing convex slope of 40 percent under wild oats, medusahead, squirreltail, soft chess, blue oak, live oak, and manzanita at 1,500 feet elevation. (Colors are for dry soil unless otherwise stated. When described December 9, 1977, the soil was moist throughout.)

Oi--0 inch to 1; oak leaf litter.

A1--1 to 5 inches; brown (7.5YR 5/2) loam, dark brown (7.5YR 3/2) moist; moderate fine, medium and coarse granular and moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and few medium roots; common very fine and fine tubular and many very fine, fine and medium interstitial pores; neutral (pH 6.7); abrupt wavy boundary. (4 to 8 inches thick.)

BAt--5 to 13 inches; pinkish gray (7.5YR 6/2) loam, brown (7.5YR 4/2) moist; moderate fine medium and coarse subangular blocky structure; slightly hard, firm, sticky and slightly plastic; many very fine, common fine and medium, and few coarse roots; many very fine, common fine and few medium tubular and common very fine and fine interstitial pores; few thin clay films on peds, bridging mineral grains and in pores; neutral (pH 6.6); clear wavy boundary. (6 to 10 inches thick.)

Bt1--13 to 21 inches; pinkish gray (7.5YR 6/2) clay loam, brown (7.5YR 4/2) moist; weak fine and medium prismatic structure, parting to fine and medium angular blocky; hard, firm, sticky and plastic; common very fine, fine, medium and coarse roots; few very fine tubular and common very fine and fine interstitial pores; few thin clay films on peds, bridging mineral grains and in pores; moderately acid (pH 5.6); abrupt wavy boundary. (8 to 10 inches thick.)

Bt2--21 to 46 inches; pale brown (10YR 6/3) clay, dark yellowish brown (10YR 3/4) moist; moderate medium and coarse prismatic structure, parting to medium coarse and very coarse angular blocky; hard, firm, sticky and plastic; few very fine, fine and coarse roots; few very fine tubular and common very fine, fine, and few medium interstitial pores; many moderately thick and thick clay films bridging mineral grains, on peds and in pores; common slickensides; moderately acid (pH 5.6); abrupt irregular boundary. (22 to 32 inches thick.)

R--46 inches; hard, fractured sandstone. Fractures are 25 to 100 mm apart and up to 5 mm wide with soil in cracks.

TYPE LOCATION: Lake County, California; about 3 miles northwest of Upper Lake; about 75 feet from ridgetop on a northwest aspect, 300 feet east and 25 feet north of the southwest corner of the NE 1/4,SW 1/4, section 28, T.16 N., R.10 W.

RANGE OF CHARACTERISTICS: Thickness of the solum and depth to bedrock is 40 to 60 inches. The mean annual soil temperature is 59 degrees to 63 degrees F. The soil between the depths of 6 and 18 inches is dry in all parts from June 1 to October 31 and is moist in all parts from January 1 to April 30. Slickensides commonly occur but are not present in all pedons. Base saturation is assumed to be >75 percent throughout the argillic horizon.

The A horizon is 7.5YR 4/2, 5/2; 10YR 5/2, 5/3, 6/2 or 6/3. Moist color is 7.5YR 3/2; 10YR 3/2 or 3/3. Dark colored surface layers, high in organic matter, are not thick enough to qualify for a mollic epipedon. Texture is loam or clay loam and is 15 to 30 percent clay. Reaction is slightly acid to slightly alkaline.

The Bt horizon is 7.5YR 5/2, 5/3, 5/4, 6/2; 10YR 4/2, 4/3, 5/2, 5/3, 5/4, 6/3, or 6/4. Moist color is 7.5YR 4/2, 4/4, 3/4; 10YR 3/3, 3/4, 4/3, 4/4 or 5/3. Texture is clay loam or clay and is 30 to 55 percent clay. The particle-size control section averages 35 to 50 percent clay. Reaction is medium acid to slightly alkaline.

COMPETING SERIES: These are the Azule, Rincon and Skyhigh series. Azule and Skyhigh soils are 20 to 40 inches deep to bedrock. Rincon soils are greater than 60 inches deep and formed on alluvial fans and terraces. In addition these soils are dry from May to November or early December.

GEOGRAPHIC SETTINGS: Sleeper soils are on hills and mountains. Slopes are 5 to 50 percent. Elevations are from 800 to 2,500 feet. The climate is subhumid with cool wet winters and hot dry summers. Mean January temperature is 41 degrees F; mean July temperature is 68 degrees F; mean annual temperature varies from 55 degrees to 60 degrees F. The mean annual precipitation varies from 18 to 40 inches. The frost-free season varies form 155 to 210 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Skyhigh and the Millsholm soils. Millsholm soils are 10 to 20 inches deep.

DRAINAGE AND PERMEABILITY: Well drained; medium to very high runoff; slow permeability.

USE AND VEGETATION: Used for livestock grazing and watershed. Vegetation is wild oats, soft chess, filaree, medusahead, blue oak and live oak.

DISTRIBUTION AND EXTENT: Interior Coast Range Mountains of California. The soils are not extensive.

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

SERIES ESTABLISHED: Upper Lake area, Lake County, California, 1983.

---

National Cooperative Soil Survey
U.S.A.