LOCATION CHENUIS                 WA

Established Series
Rev. PHR/TMR/MPR
07/2017

CHENUIS SERIES

Landscape--Cascade Mountains
Landform--mountain slopes, glacial-valley walls, cirques, ridges
Slope--5 to 100 percent
Parent material--mixed volcanic ash and colluvium derived from andesite
Mean annual precipitation--about 2300 mm
Mean annual air temperature--about 3 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Medial-skeletal, glassy Humic Vitricryands

TYPICAL PEDON: Chenuis gravelly medial coarse sandy loam in a meadow on an east-facing glacial-valley wall with a slope of 45 percent and at an elevation of 1420 m (When described on September 26, 2013, the soil was moist throughout.)

Oi--0 to 3 cm; slightly decomposed plant material from grasses and forbs; many fine interstitial pores; very strongly acid (pH 4.5); clear smooth boundary

A1--3 to 15 cm; gravelly medial coarse sandy loam, brown (10YR 4/3) dry, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and medium, common coarse, and few very coarse roots; many fine and very fine interstitial pores; 15 percent andesite gravel and 10 percent andesite cobbles; strongly acid (pH 5.2); abrupt wavy boundary

A2--15 to 30 cm; very gravelly medial sandy loam, dark grayish brown (10YR 4/2) dry, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium, and coarse roots; many fine and very fine interstitial pores; 30 percent andesite gravel and 15 percent andesite cobbles; strongly acid (pH 5.2); clear wavy boundary

Bw1--30 to 65 cm; extremely cobbly medial sandy loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine, fine, medium, and coarse roots; many fine and very fine interstitial pores; 25 percent andesite gravel, 30 percent andesite cobbles, and 10 percent andesite stones; strongly acid (pH 5.2); clear irregular boundary

Bw2--65 to 150 cm; extremely cobbly medial sandy loam, grayish brown (10YR 5/2) dry, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine, fine, medium, and coarse roots; many fine and very fine interstitial pores; 30 percent andesite gravel, 30 percent andesite cobbles, and 10 percent andesite stones; strongly acid (pH 5.4)

TYPE LOCATION: Lewis County, Washington, in the Reflection Lakes area, between Faraway Rock and Sunbeam Creek, about 2 km southeast of Paradise Ranger Station in Mount Rainier National Park; about 515 m north and 240 m east of the southwest corner of section 20, T. 15 N., R. 9 E., Willamette Meridian; Mount Rainier East, Washington, U.S. Geological Survey quadrangle; latitude 46.773699 degrees north, longitude -121.715468 degrees west, datum WGS 84 (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--1 to 7 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October
Thickness of umbric epipedon--25 to 100 cm

All mineral horizons
*Reaction--4.5 to 5.5
*Volcanic glass content--50 to 75 percent
*Ammonium oxalate Al plus 1/2 Fe--greater than 1.0 percent

Particle-size control section
*Clay content--1 to 10 percent
*Total pararock and rock fragment content--35 to 75 percent

O horizon
*In lieu of texture--slightly decomposed plant material, moderately decomposed plant material
*Combined thickness--as much as 5 cm

A1 horizon
*Hue--10YR, 7.5YR
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--1 to 3 moist or dry
*Fine-earth texture--medial coarse sandy loam, medial sandy loam
*Pararock and rock fragment content--15 to 35 percent total, including 0 to 15 percent pumice paragravel, 15 to 35 percent andesite gravel, and 0 to 15 percent andesite cobbles
*Thickness--10 to 20 cm

A2 horizon
*Hue--10YR, 7.5YR
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--1 to 3 moist or dry
*Fine-earth texture--medial sandy loam, medial coarse sandy loam, medial loamy sand
*Pararock and rock fragment content--35 to 60 percent total, including 0 to 20 percent pumice paragravel, 20 to 45 percent andesite gravel, 15 to 30 percent andesite cobbles, and 0 to 10 percent andesite stones
*Thickness--15 to 50 cm

Bw horizon
*Hue--7.5YR, 10YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--2 to 6 moist or dry
*Fine-earth texture--medial sandy loam, medial loamy coarse sand, medial loam
*Pararock and rock fragment content--35 to 75 percent total, including 0 to 20 percent pumice paragravel, 20 to 50 percent andesite gravel, 15 to 35 percent andesite cobbles, and 0 to 15 percent andesite stones
*Combined thickness--80 to 130 cm

COMPETING SERIES:
Sarvant--lithic contact within a depth of 100 cm (moderately deep)

GEOGRAPHIC SETTING:
Elevation--1110 to 2390 m
Climate--cool, dry summers; cold, wet winters
Mean annual precipitation--1550 to 4000 mm
Mean annual air temperature--0 to 6 degrees C
Frost-free period--30 to 60 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Tatoosh--lithic contact within a depth of 25 to 50 cm (shallow); in similar landform positions not associated with talus fields
Burroughs--lithic contact within a depth of 50 to 100 cm (moderately deep); in similar landform positions not associated with talus fields
Littletahoma--no lithic contact within a depth of 150 cm (very deep); in similar landform positions not associated with talus fields
Sarvant--lithic contact within a depth of 50 to 100 cm (moderately deep); in similar landform positions
Mountwow--aquic conditions with an upper limit of 25 cm from the mineral soil surface; in concave areas of similar landforms that receive water from adjacent slopes
Unicornpeak--ochric epipedon; albic and spodic horizons; in similar forested landform positions
Williwakas--aquic conditions within 25 cm of the mineral soil surface; in concave areas of similar landforms that receive water from adjacent slopes

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--high or very high throughout

USE AND VEGETATION:
Use--wildlife habitat, recreation
Potential natural vegetation--subalpine and alpine meadows composed of Cascade mountain ash, Cascade huckleberry, beargrass, Columbia brome, alpine aster, leafy aster, arctic lupine, Sitka valerian, common yarrow, smooth woodrush, phlox, kinnikinnick, and occasional scattered subalpine fir, mountain hemlock, and whitebark pine

DISTRIBUTION AND EXTENT: Central Cascade Mountains, Washington; MLRA 3; moderate extent

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

SERIES ESTABLISHED: Mount Rainier National Park, Pierce County, Washington; 2014; name from Chenuis Mountain in Mount Rainier National Park

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 3 to 103 cm
*Umbric epipedon--zone from 3 to 30 cm
*Cambic horizon--zone from 30 to 150 cm
*Andic soil properties--zone from 3 to 150 cm
*Volcanic glass--zone from 3 to 150 cm

3/2017--This official series description was updated according to SSR1 Technical Note 11--Content and Format of Official Series Descriptions (revised 12/2015). Most of the changes were in formatting; no major technical changes were made.

---

National Cooperative Soil Survey
U.S.A.