LOCATION OLOMOUNT WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, mixed, frigid Typic Haploxerands
TYPICAL PEDON: Olomount gravelly loam - forested. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Oi--2 1/2 to 2 inches; leaves, needles and mosses.
Oe--2 inches to 0; partially decomposed litter.
A--0 to 2 inches; very dark grayish brown (10YR 3/2) gravelly silt loam, grayish brown (10YR 5/2) dry; moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic or weakly smeary; common fine and medium roots; many fine interstitial pores; 20 percent pebbles; strongly acid (pH 5.4); clear smooth boundary. (0 to 6 inches thick)
Bs1--2 to 7 inches; reddish brown (5YR 5/4) gravelly loam, light reddish brown (5YR 6/4) dry; weak medium subangular blocky; slightly hard, friable, slightly sticky, slightly plastic or weakly smeary; common fine and medium roots; few fine interstitial pores; 20 percent pebbles; moderately acid (pH 5.8); clear smooth boundary. (4 to 9 inches thick)
Bs2--7 to 18 inches; dark brown (7.5YR 4/4) gravelly loam, brown (7.5YR 5/4) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic or weakly smeary; few fine and medium roots; few fine interstitial pores; 20 percent pebbles; moderately acid (pH 6.0); clear smooth boundary. (6 to 19 inches thick)
BC1--18 to 27 inches; dark brown (7.5YR 4/4) very gravelly loam, brown (7.5YR 5/4) dry; massive; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; few fine and medium roots; 60 percent pebbles; slightly acid (pH 6.2); clear smooth boundary. (6 to 11 inches thick)
BC2--27 to 32 inches; dark brown (7.5 YR 4/4) extremely gravelly loam, brown (7.5YR 5/4) dry; massive; slightly hard, friable, slightly sticky, slightly plastic or weakly smeary; few fine roots; 80 percent pebbles; slightly acid (pH 6.2); abrupt smooth boundary. (0 to 10 inches thick)
2R--32 inches; andesite.
TYPE LOCATION: Snohomish County, Washington; 1,400 feet east and 2,300 feet south of the northwest corner of sec. 33, T. 31 N., R. 7 E.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in the moisture control section for 45 to 60 consecutive days. The mean annual soil temperature at a depth of 20 inches ranges from 35 to 47 degrees F. Depth to bedrock ranges from 20 to 40 inches. Coarse fragments in the control section average from 35 to 60 percent by weighted average.
The A horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 through 4 moist or dry. Reaction is extremely acid or moderately acid.
The Bs horizon has hue of 5YR or 7.5YR, value of 2 through 6 moist, 3 through 7 dry, and chroma of 3 through 6 moist or dry. It is gravelly loam, cobbly loam or gravelly silt loam.
The BC horizon has hue of 10YR or 7.5YR, value of 4 or 5 moist, 5 or 6 dry, and chroma of 3 through 6 moist or dry. It is extremely or very gravelly loam or silt loam. This horizon is moderately acid or slightly acid.
COMPETING SERIES: These are the Cupples, Danforth, Larrupin, Littlejohn, Montborne, Oakes, Pitcher, Rinker, Sorensen, and Winnecook series. Cupples and Montborne soils are 20 to 40 inches deep to a paralithic contact with dense glacial till. Danforth and Larrupin soils are more than 40 inches deep. Littlejohn soils have a mantle of volcanic ash. Rinker and Winnecook soils are 35 to 70 percent phyllite, slate or shale in the particle-size control section.
GEOGRAPHIC SETTING: These soils are on mountain slopes at elevations ranging from 800 to 1,800 feet. Slope is 3 to 90 percent. These soils formed in glacial till and volcanic ash and alluvium from andesite. Olomount soils have a cool marine climate with wet winters and dry summers. The average annual precipitation ranges from 60 to 80 inches, the mean January temperature is 29 degrees F, and the mean July temperature is 59 degrees F. The mean annual temperature is about 45 degrees F. The frost-free season is 120 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Elwell, Getchell, Ogarty, Oso, Skykomish, and Tokul soils. Elwell, Getchell, Skykomish, and Tokul soils lack a lithic contact within a depth of 40 inches. Ogarty and Tokul soils are mesic.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used for woodland and wildlife habitat. Native vegetation is western hemlock, Douglas-fir, western redcedar, Pacific silver fir, red alder, and bigleaf maple with an understory of western brackenfern, red huckleberry, salal, deer fern, salmonberry, Oregon- grape, trailing blackberry and vine maple.
DISTRIBUTION AND EXTENT: West slopes of the Cascade Mountains in northwestern Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snohomish County, Washington, 1979.
REMARKS: Classification only updated 3/94 because of recent amendments to Soil Taxonomy. Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the mineral surface to 2 inches, a cambic horizon from 2 to 18 inches, and a lithic contact at 32 inches.