LOCATION SKIYOU WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy-skeletal, amorphic over isotic, mesic Typic Vitrixerands
TYPICAL PEDON: Skiyou gravelly silt loam - on a 13 percent convex southwest-facing slope under a forest canopy. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
01--1 1/2 inches to 0; undecomposed leaves, branches, and twigs.
A1--0 to 3 inches; very dark grayish brown (10YR 3/2) silt loam, dark brown (10YR 4/3) dry; weak fine granular structure; soft, very friable, nonsticky, slightly plastic and weakly smeary; common very fine and fine roots; many very fine irregular pores; 10 percent rounded pebbles; NaF pH less than 9.4; medium acid (pH 5.6); clear wavy boundary. (0 to 4 inches thick)
B21ir--3 to 14 inches; reddish brown (5YR 4/4) gravelly silt loam, brown (7.5YR 5/4) dry; weak medium granular structure; soft, very friable, nonsticky, nonplastic and weakly smeary; few very fine and fine roots; common very fine irregular pores; 20 percent rounded pebbles; NaF pH 12.0; strongly acid (pH 5.4); gradual smooth boundary. (9 to 13 inches thick)
B22--14 to 23 inches; dark brown (7.5YR 4/4) gravelly loam, yellowish brown (10YR 5/4) dry; weak fine granular and weak fine subangular blocky structure; soft, very friable, nonsticky, slightly plastic and weakly smeary; few very fine and fine roots; common fine irregular pores; 20 percent rounded pebbles; NaF pH 12.0; strongly acid (pH 5.4); clear smooth boundary. (6 to 14 inches thick)
2C1--23 to 32 inches; dark yellowish brown (10YR 4/4) very gravelly fine sandy loam, light yellowish brown (2.5Y 6/4) dry; weak medium subangular blocky and weak medium granular structure; soft, very friable, nonsticky and nonplastic; few fine roots; common fine irregular pores; 35 percent rounded pebbles and channers; strongly acid (pH 5.5); abrupt smooth boundary. (8 to 10 inches thick)
2C2--32 to 60 inches; light olive brown (2.5Y 5/4) very gravelly fine sandy loam, pale olive (5Y 6/3) dry; massive; soft, friable, nonsticky and nonplastic; few very fine roots; common very fine irregular pores; 55 percent rounded pebbles and channers; strongly acid (pH 5.5).
TYPE LOCATION: Skagit County, Washington; 2,100 feet south and 240 feet east of the northwest corner sec. 33, T. 35 N., R. 5 E.
RANGE IN CHARACTERISTICS: The solum is 21 to 38 inches thick. The mean annual soil temperature is 51 to 55 degrees F. Soil reaction is strongly acid or medium acid.
The A1 horizon has hue of 7.5YR or 10YR, value of 2 through 4 moist, 4 or 5 dry, and chroma of 1 or 2 moist and dry. Some pedons lack an A1 horizon.
The B horizon has hue of 5YR, 7.5YR, or 10YR, value of 3 through 5 moist, 4 through 6 dry, and chroma of 3 or 4 moist and 4 through 6 dry. It is silt loam, loam, gravelly silt loam, or gravelly loam and averages 10 to 30 percent rock fragments. Some pedons have a B3 horizon.
The 2C horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 through 6 moist, 5 through 7 dry, and chroma of 2 through 4 moist and dry. It is very gravelly sandy loam, very gravelly fine sandy loam, or very gravelly loam and averages 35 to 65 percent rock fragments.
COMPETING SERIES: These are the Eloika, Nargar, and Winston series in other families. Eloika soils are medial over loamy. Nargar and Winston soils are medial over sandy or sandy-skeletal.
GEOGRAPHIC SETTING: Skiyou soils are on glacially modified uplands. Slopes range from 0 to 30 percent. Elevation is 150 to 1,100 feet. These soils formed in loess and volcanic ash overlying unconsolidated mixed glacial till. The average annual precipitation is 60 to 70 inches. The mean annual temperature is 49 to 52 degrees F. The average January temperature is about 37 degrees F., and the average July temperature is about 65 degrees F. The frost-free season is 180 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Skipopa, Squires, Thornwood, and Vanzandt soils. Skipopa soils are medial over clayey. Squires soils are moderately deep to a lithic contact. Thornwood soils are sandy-skeletal. Tokul soils have a duripan. Vanzandt soils are moderately deep to a paralithic contact with dense glacial till.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used for woodland, wildlife habitat, and homesites. Native vegetation is Douglas-fir, western redcedar, red alder, and vine maple with an understory of blackberry, salmonberry, western swordfern, western brackenfern and nettle.
DISTRIBUTION AND EXTENT: Northwestern Washington. This soil is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED:
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.