LOCATION CAYUSE WAEstablished Series
TAXONOMIC CLASS: Ashy over medial, glassy over amorphic Humic Vitricryands
TYPICAL PEDON: Cayuse sandy loam - on an 8 percent convex
rounded ridge crest, under subalpine fir and grass
vegetation at an elevation of 5,600 feet. (Colors are for
moist soil unless otherwise stated. All textures
are apparent field textures.)
O--l/4 inch to 0; moss, twigs, needles (l/4 to 1 inch
thick)
A1--0 to 4 inches; very dark grayish brown (10YR 3/2)
sandy loam (volcanic ash), dark brown (10YR 4/3) dry;
weak fine and medium subangular blocky structure; soft, very
friable, nonsticky, nonplastic; weakly smeary;
many very fine and common fine roots; very strongly acid (pH
5.0), NaF pH 12.0+; clear smooth boundary. (1 to
6 inches thick)
A2--4 to 13 inches; dark brown (10YR 3/3) sandy loam
(volcanic ash), dark yellowish brown (10YR 4/4) dry;
weak fine and medium subangular blocky structure; soft, very
friable, nonsticky, slightly plastic; weakly
smeary; many very fine, fine, and medium roots; 10 percent
fine pebbles; very strongly acid (pH 5.0), NaF pH
12.0+; clear smooth boundary. (5 to 10 inches thick)
Bw1--13 to 30 inches; brown (7.5YR 4/4) loam, (volcanic
ash), brown (7.5YR 5/4) dry; moderate medium
subangular blocky structure; slightly hard, friable,
nonsticky, slightly plastic; moderately smeary; common
fine and medium roots; 10 percent pebbles; strongly acid (pH
5.2), NaF pH 11.5; clear smooth boundary. (7 to
20 inches thick)
2Bw2--30 to 36 inches; dark yellowish brown (10YR 4/6)
gravelly loam, brownish yellow (10YR 6/6) dry;
moderate medium subangular blocky structure, slightly hard,
friable, slightly sticky, slightly plastic;
moderately smeary; few fine roots; 30 percent pebbles, 10
percent soft pebbles; strongly acid (pH 5.2), NaF pH
11.0; clear smooth boundary. (6 to 12 inches thick)
2C--36 to 60 inches; variegated dark yellowish brown
(10YR 4/4) and yellowish brown (10YR 5/6) very
gravelly loam, light yellowish brown (10YR 6/4) and brownish
yellow (10YR 6/6) dry; moderate fine and medium
angular and subangular blocky structure; hard, firm,
slightly sticky, slightly plastic; moderately smeary; few
fine roots; 40 percent pebbles, 10 percent soft pebbles,
strongly acid (pH 5.2), NaF pH 10.5.
TYPE LOCATION: Snoqualmie Pass Area, Pierce County,
Washington; Corral Pass Campground, Snoqualmie National
Forest, off of Forest Service road number 185, 2,340 feet
east and 790 feet north of the southwest corner, sec.
30 T. l8 N. R. 11 E.
RANGE IN CHARACTERISTICS: The volcanic ash mantle is 14 to
35 inches thick. Mean annual soil temperature
ranges from 36 to 40 degrees F. Reaction is moderately acid
to very strongly acid throughout.In some pedons an
0a horizon is present.
The A horizon has hue 7.5YR or 10YR, value of 2 or 3 moist,
3 through 5 dry, and chroma of 2 through 4, moist
or dry.
The Bw horizon has hue of 7.5YR or 10YR, value of 3 or 4
moist, 4 or 5 dry and chroma of 4 through 6 moist or
dry. Texture is loam or sandy loam. Rock fragments range
from 5 to 15 percent by volume.
The 2Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5
moist, 5 or 6 dry, and chroma of 4 through 6 moist or
dry. Texture is gravelly loam or gravelly sandy loam. Rock fragments range from 15 to 35 percent by volume.
The 2C horizon has value of 4 or 5 moist, 5 or 6 dry, and
chroma of 4 through 6 moist or dry. Some pedons are
variegated. Texture is very gravelly loam, gravelly loam or
very gravelly sandy loam. Rock fragments range
from 30 to 50 percent by volume.
COMPETING SERIES: These are the
Tusip and
Pustoi series.
Tusip soils lack an umbric epipedon. Pustoi soils
are ashy.
GEOGRAPHIC SETTING: Cayuse soils are on ridge crests and
sideslopes at elevations of 5,000 to 6,200 feet.
Slopes range from 8 to 90 percent. The Cayuse soils formed
in volcanic ash and pumice and residuum and
colluvium from andesite or basalt. The climate is marine
influenced with cold wet winters and cool moist
summers. The mean January temperature is about 25 degrees
F.; the mean July temperature is about 55 degrees
F.; and the mean annual temperature is about 38 degrees F.
Average annual precipitation ranges from 80 to 110
inches, with a large portion of this in the form of snow.
The frost-free season is 90 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Nimue,
Haywire, Chikamin and
Reggad soils. Nimue, Haywire, and
Chikamin have a spodic horizon and are medial-skeletal. The
Reggad soils lack a cambic horizon.
DRAINAGE AND PERMEABILITY: Well drained, moderate
permeability, slow to rapid runoff.
USE AND VEGETATION: Used for woodland, watershed, and
wildlife habitat. Vegetation is subalpine fir, western
hemlock, Pacific silver fir, and Engelmann spruce with an
understory of fawnlily, wild ginger, roughfruit
berry, tall blue huckleberry, one leaf foamflower,
bunchberry dogwood, and lambstongue fawnlily.
DISTRIBUTION AND EXTENT: Western slopes of the Cascade
Mountains in central Washington. Series is of small
extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snoqualmie Pass Area, Pierce County,
Washington, 1986.
REMARKS: Diagnostic horizons and features recognized in
this pedon are an umbric epipedon from the mineral
surface to 13 inches and a cambic horizon from 13 to 36
inches. The layer from the surface to 30 inches is
assumed to be more than 60 percent volcanic ash.