LOCATION SINLAHEKIN WA

Established Series
IRD. KH/TDT
01/2011

SINLAHEKIN SERIES

The Sinlahekin series consists of very deep, well drained soils formed in glacial outwash with an influence of volcanic ash in the surface. These soils are in glacial valleys. Slopes are 3 to 15 percent. The average annual precipitation is about 17 inches, and the average annual temperature is about 49 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Vitrandic Haploxerolls

TYPICAL PEDON: Sinlahekin ashy sandy loam on an east facing 14 percent slope at 1,800 feet elevation. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)

Oi--0 to 0.5 inch; slightly decomposed litter; abrupt smooth boundary. (0 to 1 inch thick)

A1--0.5 to 7 inches; black (10YR 2/1) stony ashy sandy loam, dark grayish brown (10YR 4/2) dry; strong medium and coarse subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine; many very fine and fine tubular pores; 10 percent cobbles, 5 percent gravel, 5 percent stones; neutral (pH 7.0); clear wavy boundary.

A2--7 to 14 inches; very dark brown (10YR 2/2) gravelly ashy very fine sandy loam, dark grayish brown (10YR 4/2) dry; moderate medium and coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine tubular pores; 10 percent gravel and 5 percent cobbles; neutral (pH 7.0); abrupt wavy boundary. (combined thickness of the A horizon is 10 to 18 inches)

2Bw1--14 to 23 inches; very dark grayish brown (10YR 3/2) cobbly sandy loam, brown (10YR 4/3) dry; moderate fine and medium subangular blocky structure; slightly hard, nonsticky and nonplastic; common very fine and fine; many very fine and fine tubular pores; 15 percent gravel and 10 percent cobbles; neutral (pH 7.2); clear wavy boundary. (9 to 15 inches thick)

2Bw2--23 to 35 inches; dark brown (10YR 3/3) extremely gravelly very fine sandy loam, yellowish brown (10YR 5/4)dry; single grained, loose, nonsticky and nonplastic; few very fine and fine and few medium roots; many very fine and fine interstitial pores; 50 percent gravel and 20 percent cobbles; slightly alkaline (pH 7.4); clear wavy boundary. (10 to 20 inches thick)

2Bk--35 to 61 inches; 90 percent extremely gravelly multicolored fine sand, 10 percent multicolored coarse sand; single grained; loose, nonsticky and nonplastic; few very fine and fine and few medium roots; many very fine and fine interstitial pores; 5 percent calcium carbonate on the underside of coarse fragments; slightly effervescent; 50 percent gravel and 20 percent cobbles; slightly alkaline (pH 7.4).

TYPE LOCATION: Okanogan County, Washington; Blue Goat Mountain Quadrangle; section 33, T. 37 N., R. 25 E.; travel 2.2 miles north on Sinlahekin Road from intersection of Fish Lake Road and Sinlahekin Road; Latitude 48 degrees, 39 minutes, 36.3 seconds North., Longitude 119 degrees, 41 minutes, 78.7 seconds West; NAD 83. (position measured by Garmin GPS unit.)

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 50 degrees F. These soils are usually moist but are dry for 75 to 90 consecutive days following the summer solstice. The mollic epipedon is 10 to 18 inches thick. The particle-size control section averages 3 to 8 percent clay and 35 to 60 percent rock fragments. Reaction is slightly acid to moderately alkaline increasing with depth.

A horizon
Value: 2 or 3 moist, 4 or 5 dry.
Chroma: 1 or 2 moist, 2 or 3 dry.
Fine-earth texture: ashy sandy loam or ashy very fine sandy loam.
It has 5 to 20 percent glass and acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.4 to 1.0 percent, and 15-bar water retention of 5 to 10 percent for air dried samples.
Structure: subangular blocky or granular
Gravel: 5 to 25 percent gravel.
Cobbles: 0 to 10 percent cobbles.
Stones: 0 to 15 percent surface stones and boulders.
Base saturation (sum): 50 to 75 percent

2Bw horizon
Value: 2 to 4 moist, 4 to 6 dry.
Chroma: 2 to 4 dry or moist.
Fine-earth texture: sandy loam or very fine sandy loam.
Gravel: 15 to 50 percent gravel
Cobbles: 0 to 25 percent.
Stones: 0 to 10 percent.

2Bk horizon
Value: 4 or 5 moist, 6 or 7 dry.
Chroma: 2 to 4 dry or moist.
Fine-earth texture: sandy loam, coarse sandy loam, loamy sand, or fine sand.
Gravel: 25 to 50 percent gravel.
Cobbles: 5 to 30 percent cobbles
Stones: 0 to 10 percent.

COMPETING SERIES: These are the Borgeau, Emily, Lenz, Louiecreek, Peka, Raiso, Speigle, Vanbrunt, and Whitestone series. These soils are all on mountain slopes. Borgeau soils have a particle-size control section with 10 to 18 percent clay. Emily soils have a particle size control section with 25 to 35 percent clay. Lenz, Raiso, and Vanbrunt soils are moderately deep to a lithic contact. Louiecreek soils have a particle-size control section that averages 8 to 15 percent clay. Peka soils have a densic contact. Speigle soils have a particle-size control section 10 to 20 percent clay. Whitestone soils have angular rock fragments.

GEOGRAPHIC SETTING: Sinlahekin soils are in glacial valleys. These soils formed in glacial outwash with an influence of volcanic ash in the surface. Slopes are 3 to 15 percent. Elevations range from 1,500 to 2,000 feet. The climate is characterized by warm, dry summers and cold, moist winters. The mean annual precipitation is 16 to 18 inches. The mean January temperature is about 25 degrees F.; mean July temperature is about 68 degrees F.; and the mean annual air temperature is about 49 degrees F. The frost-free period is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hunters and the competing Peka soils. Hunters soils are fine-silty and are in depressions. Peka soils are on fans adjacent to mountains.

DRAINAGE AND PERMEABILITY: Well drained, moderately rapid permeability.

USE AND VEGETATION: Grazing, wildlife habitat, and watersheds are the principal uses. The native vegetation is scattered ponderosa pine, arrowleaf balsamroot, bluebunch wheatgrass, and needlegrass.

DISTRIBUTION AND EXTENT: North-central Washington; MLRA 43A. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Okanogan County, Washington, 2008.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Vitrandic soil properties: 1 to 16 inches.
Mollic epipedon: 0.5 to 14 inches.
Cambic horizon: 14 to 35 inches.
Particle-size control section: 10.5 to 40.5 inches.
Rock fragments: 35 to 60 percent rock fragments in the particle-size control section.

National Cooperative Soil Survey
U.S.A.