LOCATION LONGSWAMP          WA
Established Series
Rev. BJD/TDT
07/2005

LONGSWAMP SERIES


The Longswamp series consists of very deep, moderately well drained soils formed in till and alluvium from mixed sources with a component of volcanic ash in the upper part. These
soils are on footslopes and gently sloping drainage sideslopes of mountains. The average annual precipitation is about 28 inches, and the average annual temperature is about 40 degrees F.

TAXONOMIC CLASS: Fine-loamy, isotic Vitrandic Haplocryolls

TYPICAL PEDON: Longswamp ashy loam, on a south facing 22 percent slope at an elevation of 4,730 feet in a mixed aspen and Engelmann Spruce forest. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)

A1--0 to 7 inches; very dark grayish brown (10YR 3/2) ashy loam, black (10YR 2/1) moist; moderate fine and medium subangular blocky structure parting to moderate fine granular; soft, very friable, nonsticky and nonplastic; common very fine, fine, and medium and few coarse roots; common very fine and fine pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (4 to 7 inches thick)

A2--7 to 20 inches; very dark grayish brown (10YR 3/2) ashy loam, black (10YR 2/1) moist; moderate fine and medium subangular blocky structure parting to moderate fine granular; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium and coarse roots; common very fine and fine pores; 5 percent gravel and 3 percent cobbles; neutral (pH 6.8); clear wavy boundary. (8 to 13 inches thick)

2AC--20 to 25 inches; grayish brown (10YR 5/2) cobbly sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium and few coarse roots; common very fine and fine pores; 15 percent gravel, 10 percent cobbles and 2 percent stones; neutral (pH 7.0); clear wavy boundary. (3 to 7 inches thick)

2C--25 to 39 inches; grayish brown (2.5Y 5/2) gravelly sandy clay loam, dark grayish brown (2.5Y 4/2) moist; massive; hard, firm, slightly sticky and slightly plastic; common very fine and fine and few medium roots; few very fine and fine pores; common fine and medium prominent strong brown (7.5YR 5/6) redox concentrations; 25 percent gravel, 2 percent cobbles, and 2 percent stones; neutral (pH 6.8); clear wavy boundary. (14 to 22 inches thick)

3Cg--39 to 60 inches; light brownish gray (2.5Y 6/2) gravelly silt loam, grayish brown (2.5Y 5/2) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; few fine and medium roots; few very fine pores; common medium and coarse prominent strong brown (7.5YR 5/6) redox concentrations; 15 percent gravel and 2 percent cobbles; neutral (pH 7.0).

TYPE LOCATION: Okanogan County, Washington; about 11 miles west of Loomis, Washington; 2,400 feet north and 1,000 feet west of the southeast corner of section 20, T. 39 N., R. 24 E. (Latitude 48 degrees, 51 minutes, 51 seconds N., Longitude 119 degrees, 50 minutes, 48 seconds W.)

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 38 to 41 degrees F. Mean summer soil temperature ranges from 42 to 46 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 45 to 60 consecutive days following the summer solstice. Depth to redoximorphic features range from 30 to 45 inches. These soils have a water table 36 to 60 inches from the soil surface, March through June. The particle-size control section averages 15 to 30 percent rock fragments and 20 to 30 percent clay. The mollic epipedon is 16 to 25 inches thick.

The A horizon has chromas of 1 or 2 moist. It has an estimated bulk density of 1.15 to 1.25 g/cc, volcanic glass content of 5 to 20 percent, 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.

The 2AC horizon has values of 4 or 5 dry, 3 or 4 moist, and chroma of 2 or 3 dry or moist. It is cobbly sandy clay loam, gravelly loam or clay loam. It has 5 to 15 percent gravel, 0 to 10 percent cobbles, and 0 to 2 percent stones.

The 2C horizon has hues of 2.5Y and 10YR, values of 5 or 6 dry, 4 or 5 moist, and chromas of 2 or 3 dry or moist. It is gravelly sandy clay loam, gravelly loam or clay loam. It has 15 to 25 percent gravel, 0 to 5 percent cobbles, and 0 to 2 percent stones. Reaction is slightly acid to neutral.

The 3Cg horizon has hues of 2.5Y and 10YR, values of 5 or 6 dry, 4 or 5 moist, and chromas of 2 or 3 dry or moist. It is gravelly silt loam, gravelly clay loam or gravelly sandy clay loam. It has 15 to 25 percent gravel, 0 to 5 percent cobbles and 0 to 2 percent stones. Reaction is slightly acid to neutral.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Longswamp soils are on footslopes and gently sloping drainage sideslopes. These soils are usually on southerly aspects at elevations of 3,600 to 5,500 feet. Slopes are 15 to 35 percent. These soils formed in till and alluvium from mixed rock sources with a component of volcanic ash in the upper part. The average annual precipitation ranges from 20 to 30 inches. The average January temperature ranges from 18 to 22 degrees F., and the average July temperature ranges from 52 to 58 degrees F. The average annual air temperature ranges from 37 to 43 degrees F. The frost-free season is 70 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Burget, Crocamp, Myerscreek, Sitdown and Toats soils. Burget soils are 10 to 20 inches to weathered granite on shoulders and ridges of open south slopes. Crocamp soils are 40 to 60 inches to bedrock on open south slopes. Myerscreek soils are very deep formed in till with a mantle of volcanic ash 7 to 14 inches thick. Sitdown soils are very deep formed in sandy-skeletal outwash and till with a mantle of volcanic ash 7 to 14 inches thick. Toats soils are very deep and have an umbric epipedon on open backslopes with southerly aspects.

DRAINAGE AND PERMEABILITY: Moderately well drained; medium runoff; moderately slow permeability. Longswamp soils have a water table 36 to 60 inches from the surface, March to June.

USE AND VEGETATION: Used for wildlife habitat, watershed, recreation and livestock grazing. Native vegetation is quaking aspen and Engelmann spruce with an understory of pinegrass, western meadowrue, lupine, common yarrow, russett buffaloberry and brome spp.

DISTRIBUTION AND EXTENT: Northcentral Washington. This series is of small extent.

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

SERIES ESTABLISHED: Okanogan National Forest, Okanogan County, Washington, 2005.

REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon - 0 to 25 inches (A1,A2 and 2AC horizons)
Depth to redoximorphic features range from 30 to 45 inches.
PSCS - zone from 10 to 40 inches (part of the A2, 2AC, 2C and part of 3Cg horizons)

PSCS- zone from 10 to 40 inches (part of the A2, 2AC, 2C and part of 3Cg horizons)

Vitrandic properties from 0 to 20 inches.


National Cooperative Soil Survey
U.S.A.