LOCATION LITTLETAHOMA WA
Established Series
IRD. TMR/MPR
07/2017
LITTLETAHOMA SERIES
Landscape--Cascade Mountains
Landform--mountain slopes, glacial valley walls, cirques, ridges, parklands
Slope--10 to 100 percent
Parent material--volcanic ash over colluvium derived from andesite
Mean annual precipitation--about 2500 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, glassy Humic Vitricryands
TYPICAL PEDON: Littletahoma paragravelly medial sandy loam on a north-facing, 45-percent slope of a ridge at an elevation of 1905 m (When described on October 27, 2011, the soil was frozen at the surface and moist throughout.)
A1--0 to 12 cm; paragravelly medial sandy loam, very dark gray (10YR 3/1) dry, black (10YR 2/1) moist; moderate medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and few medium roots; many very fine and fine interstitial pores; 15 percent pumice paragravel; strongly acid (pH 5.2); clear wavy boundary
A2--12 to 70 cm; very paragravelly medial sandy loam, very dark grayish brown (10YR 3/2) dry, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium roots; many very fine and fine interstitial pores; 20 percent pumice paragravel; strongly acid (pH 5.2); clear wavy boundary
A3--70 to 90 cm; paragravelly medial sandy loam, brown (10YR 4/3) dry, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium roots; many very fine and fine interstitial pores; 20 percent pumice paragravel; strongly acid (pH 5.2); clear irregular boundary
Bw1--90 to 110 cm; paragravelly medial fine sandy loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; moderate coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine to medium roots; common very fine and fine irregular pores; 20 percent pumice paragravel; strongly acid (pH 5.4); clear wavy boundary
2Bw2--110 to 150 cm; gravelly medial sandy loam, yellowish brown (10YR 5/6) dry, dark yellowish brown (10YR 3/6) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine and fine irregular pores; 20 percent andesite gravel and 10 percent andesite cobbles; strongly acid (pH 5.4)
TYPE LOCATION: Pierce County, Washington, on a ridge north of the White River in the Yakima Park area, about 1.5 km southeast of the Sunrise Ranger Station in Mount Rainier National Park; about 450 m north and 90 m west of the southeast corner of section 35, T. 17 N., R. 9 E., Willamette Meridian; White River Park, Washington, U.S. Geological Survey quadrangle; latitude 46.911726 degrees north, longitude -121.621874 degrees west, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--2 to 7 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October
Depth to lithologic discontinuity--70 to 120 cm
Thickness of umbric epipedon--25 to 100 cm
Pararock and rock fragments--pumice paragravel typically in upper part of profile, andesite gravel and cobbles typically in lower part of profile
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 rock fragment content--5 to 35 percent
A thin O horizon may be in some pedons near areas that have a subalpine coniferous canopy.
A1 horizon
*Hue--10YR, 7.5YR
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--1 or 2 moist or dry
*Fine-earth texture--medial sandy loam, medial coarse sandy loam
*Pararock fragment content--10 to 30 percent pumice paragravel
*Thickness--10 to 20 cm
A2 horizon
*Hue--10YR, 7.5YR
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--1 or 2 moist or dry
*Fine-earth texture--medial sandy loam, medial coarse sandy loam, medial loam
*Pararock fragment content--5 to 30 percent pumice paragravel
*Thickness--20 to 60 cm
A3 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 loamy sand, medial coarse sandy loam
*Pararock fragment content--5 to 30 percent pumice paragravel
*Thickness--20 to 40 cm
Bw1 horizon
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--2 to 6 moist or dry
*Fine-earth texture--medial fine sandy loam, medial sandy loam, medial loam
*Pararock and rock fragment content--15 to 35 percent total, including 10 to 30 percent pumice paragravel, 0 to 10 percent andesite gravel, and 0 to 5 andesite cobbles
*Thickness--20 to 40 cm
2Bw2 horizon
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--2 to 6 moist or dry
*Fine-earth texture--medial sandy loam, medial loam, medial coarse sandy loam
*Rock fragment content--15 to 60 percent total, including 15 to 40 percent andesite gravel, 0 to 20 percent andesite cobbles, and 0 to 10 percent andesite stones
COMPETING SERIES:
Burroughs--lithic contact within 100 cm of the surface (moderately deep)
GEOGRAPHIC SETTING:
Elevation--1150 to 2125 m
Climate--cool, dry summers; cold, wet winters
Mean annual precipitation--1550 to 3430 mm
Mean annual air temperature--1 to 6 degrees C
Frost-free period--30 to 60 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Burroughs--lithic contact within 50 to 100 cm of the surface (moderately deep); in similar landform positions
Tatoosh--lithic contact within 25 to 50 cm of the surface (shallow); 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
Ipsut,
Owyhigh,
Tipsoo--ochric epipedon; albic and spodic horizons; on similar forested landforms
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 Columbia brome, alpine aster, leafy aster, western columbine, arctic lupine, Sitka valerian, common yarrow, smooth woodrush, and occasional scattered subalpine fir and mountain hemlock
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 Little Tahoma Peak in Mount Rainier National Park
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from the surface to a depth of 100 cm
*Umbric epipedon--zone from the surface to a depth of 90 cm
*Cambic horizon--zone from 90 to 150 cm
*Andic soil properties--zone from the surface to a depth of 150 cm
*Volcanic glass--zone from the surface to a depth of 150 cm
*Depth to lithologic discontinuity--110 cm
*Distinguishable tephra layers--Mount Rainier X and Mount St. Helens Wn tephra (A1 horizon), Mount Rainier C tephra (A2 horizon), Mount St. Helens Yn tephra (A3 horizon), Mount Rainier F tephra (Bw1 horizon)
7/2017--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.