LOCATION MOUNTDECEPTION WA
Tentative Series
IRD. MGR/AJF/MPR
01/2025
MOUNTDECEPTION SERIES
Landscape--mountains
Landform--glacial valley walls and colluvial aprons
Slope--15 to 60 percent
Parent material--colluvium from metasedimentary rock
Mean annual precipitation--about 2250 mm
Mean annual air temperature--about 10 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Andic Dystrudepts
TYPICAL PEDON: Mountdeception very gravelly silt loam on an east facing, forested colluvial apron with a slope of 25 percent and an elevation of 462 m. (The soil was moist throughout when described.)
Oi--0 to 2 cm; slightly decomposed plant material; abrupt wavy boundary
A--2 to 16 cm; very dark grayish brown (10YR 3/2) dry, very dark brown (10YR 2/2) very gravelly silt loam; moderate very fine granular structure; soft, very friable, slightly sticky, slightly plastic, moderately smeary; common very fine and fine roots and few course roots; common medium tubular and many fine irregular and common coarse tubular pores; 40 percent gravel; very strongly acid (pH 4.6); abrupt wavy boundary
Bw1--16 to 48 cm; dark grayish brown (10YR 4/2) dry, very dark grayish brown (10YR 3/2) very gravelly silt loam; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic, slightly smeary; common very fine to medium roots; common fine irregular and interstitial and common coarse tubular pores; 40 percent gravel; very strongly acid (pH 4.7); clear wavy boundary
Bw2--48 to 78 cm; brown (10YR 4/3) dry, dark brown (10YR 3/3) very gravelly silt loam; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, moderately plastic; few very fine and common fine roots; common fine irregular and few fine interstitial pores; 40 percent gravel, 5 percent cobbles; very strongly acid (pH 4.8); clear wavy boundary
Bw3--78 to 150 cm; yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 4/4) very gravelly silt loam; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, moderately plastic; few fine roots; few very fine irregular pores; 40 percent gravel, 5 percent cobbles; very strongly acid (pH 4.8); clear smooth boundary
TYPE LOCATION: Jefferson County, Washington, on the Duckabush Trail about half a mile E of Ten Mile Camp in Olympic National Park.
Latitude--47.676624
Longitude-- -123.202428
Datum--WGS84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--8 to 13 degrees C
Particle size control section
*Clay content--8 to 17 percent
*Total rock fragment content--35 to 60 percent
*Gravel content--25 to 60 percent
*Cobble content--0 to 30 percent
*Stone content--0 to 20 percent
O horizon
Thickness--0 to 12 cm
A horizon
Hue--10YR or 7.5YR
Value--2 or 3 dry or moist
Chroma--1 to 3 dry or moist
Fine-earth texture--silt loam, loam, sandy loam
Clay content--8 to 17 percent
Total rock fragment content--20 to 50 percent
Gravel content--15 to 50 percent
Cobble content--0 to 15 percent
Reaction--4.5 to 5.5
Thickness--10 to 20 cm
Bw1 and Bw2 horizons
Hue--10YR or 7.5YR
Value--3 to 5 dry or moist
Chroma--2 to 4 dry or moist
Fine-earth texture--silt loam, loam, sandy loam
Clay content--8 to 17 percent
Total rock fragment content--35 to 60 percent
Gravel content--25 to 60 percent
Cobble content--0 to 30 percent
Stone content--0 to 20 percent
Reaction--4.5 to 5.5
Combined thickness--50 to 80 cm
Bw3 horizon
Hue--10YR or 7.5YR
Value--3 to 5 dry or moist
Chroma--3 to 6 dry or moist
Fine-earth texture--silt loam, loam, sandy loam
Clay content--8 to 17 percent
Total rock fragment content--35 to 65 percent
Gravel content--25 to 60 percent
Cobble content--0 to 30 percent
Stone content--0 to 20 percent
Reaction--4.5 to 5.5
Thickness--60 to 100 cm
COMPETING SERIES:
Indianpass--lithic contact within 50 to 100 cm of the mineral soil surface
Sahalie--lower half of particle size control section contains a C horizon with massive structure
GEOGRAPHIC SETTINGS:
Elevation--300 to 800 m
Climate--warm, dry summers; mild, wet winters
Mean annual precipitation--1750 to 2750 mm
Mean annual air temperature--8 to 12 degrees C
Frost-free period--180 to 240 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Irely--has albic and spodic horizons; similar landforms
Butlercreek--aquic conditions within 25 to 50 cm of the mineral soil surface; depressions on similar landforms
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high or very high throughout
USE AND VEGETATION:
Use--wildlife habitat, recreation
Potential natural vegetation--Douglas-fir, western hemlock, salal, red huckleberry, western swordfern, twinflower
DISTRIBUTION AND EXTENT: Olympic Mountains, Washington; MLRA 1; large extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Olympic National Park, Jefferson County, Washington; 2023; name from Mount Deception in Olympic National Park
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 27 to 102 cm
*Ochric epipedon
*Andic subgroup features--zone from 2 to 48 cm; Ao extractable Al plus Fe is 1 to 2 percent and Db is 0.9 to 1.0 g/cm3
*Cambic horizon--zone from 16 to 150 cm
National Cooperative Soil Survey
U.S.A.