LOCATION SAUK WAEstablished Series
TAXONOMIC CLASS: Medial, amorphic, mesic Vitric Hapludands
TYPICAL PEDON: Sauk silt loam - on a 2 percent convex north facing slope under a forest canopy. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
0i--4 to 1 inch; leaves, conifer needles and twigs; abrupt smooth boundary.
0a--1 inch to 0 ; decomposed needles, leaves, and twigs; abrupt smooth boundary.
A--0 to 3 inches; brown (7.5YR 4/4) silt loam, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic, weakly smeary; common fine roots; many very fine pores; NaF pH 10.5; strongly acid (pH 5.4); clear smooth boundary. (2 to 6 inches thick)
Bs1--3 to 9 inches; yellowish brown (10YR 5/6) silt loam, brownish yellow (10YR 6/6) dry; weak medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic, weakly smeary; common fine roots; many very fine pores; NaF pH 11.0; moderately acid (pH 5.6); gradual smooth boundary. (4 to 14 inches thick)
Bs2--9 to 18 inches; yellowish brown (10YR 5/4) silt loam, light yellowish brown (2.5Y 6/4) dry; weak medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic, weakly smeary; common fine roots many very fine pores; NaF pH 11.0; moderately acid (pH 5.6); clear smooth boundary. (9 to 18 inches thick)
C--18 to 60 inches; olive brown (2.5Y 4/4) silt loam, light yellowish brown (2.5Y 6/4) dry; massive; slightly hard, friable, nonsticky, nonplastic; few fine roots; many very fine pores; NaF pH 11.0; medium acid (pH 5.6).
TYPE LOCATION: Skagit County, Washington; about 2 miles southwest of Marblemount along the Rockport-Cascade road; 1,500 feet north 1,800 feet east of the southwest corner of sec. 13, T. 35N., R. 10E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 48 to 53 degrees F. The 10 to 40 inch control section contains 3 to 8 percent clay. Weighted average rock fragments in the control section range from 0 to 10 percent by volume. Below 40 inches rock fragments range from 0 to 50 percent by weighted average.
The A horizon has hue of 7.5YR or 10YR, value of 3 through 7 dry, and chroma of 3 or 4 moist and dry.
The Bs horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 3 through 5 moist, 4 through 7 dry, and chroma of 4 through 6 moist or dry. It is silt loam, very fine sandy loam, fine sandy loam, or sandy loam.
The C horizon has hue of 10YR or 2.5Y, value of 4 or 5 moist, 5 through 7 dry, and chroma of 3 or 4 moist or dry. It is fine sandy loam, very fine sandy loam, sandy loam, or silt loam. Below 40 inches, textures can be very gravelly sandy loam, very gravelly loamy sand, or very gravelly sand. Reaction is strongly acid to moderately acid.
COMPETING SERIES: These are the Bullards, Chuckanut, Kickerville, Nati, Sehome, Squalicum, and Sulsavar soils. Bullards soils have a difference of 5 to 9 degrees F between mean summer and mean winter temperature and are sandy loam throughout the particle-size control section. Chuckanut, Sehome, Squalicum, and Sulsavar soils are gravelly in the control section. Kickerville soils have sandy-skeletal material in the lower control section. Nati soils are 20 to 40 inches deep to a lithic contact. Sehome soils are 20 to 40 inches deep to a paralithic contact with dense glacial till.
GEOGRAPHIC SETTING: Sauk soils are on terraces and have slopes of 0 to 3 percent. The soils formed in alluvium containing volcanic ash. Sauk soils occur at elevations ranging from 200 to 800 feet. The average annual precipitation range is 70 to 90 inches. The mean January temperature is about 36 degrees F, the mean July temperature is about 66 degrees F, and the mean annual temperature is about 52 degrees F. The frost-free season is 100 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barneston, Pilchuck, Larush, Rober, and Snoqualmie series. Barneston and Snoqualmie soils are sandy-skeletal. Pilchuck soils lack a spodic horizon and are sandy. Larush soils have an umbric epipedon.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow. Permeability is moderate. Some pedons have rapid permeability below 40 inches.
USE AND VEGETATION: Soils are used for pasture and woodland. Native vegetation is Douglas-fir, western hemlock, red alder, western redcedar, and with an undergrowth of bigleaf maple, Oregon-grape, western brackenfern, vine maple, red huckleberry, western swordfern, and salmonberry.
DISTRIBUTION AND EXTENT: Valleys on the west slopes of the Cascade Mountains in western Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County, Washington, 1953.
REMARKS: Classification of the series and remarks section only changed 4/94 because of recent amendments to Soil Taxonomy. Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the mineral surface to 3 inches and a cambic horizon from 3 to 18 inches.