LOCATION MOUNTMYSTERY            WA

Tentative Series
IRD. MGR/AJF/MPR
01/2025

MOUNTMYSTERY SERIES

Landscape--mountains
Landform--colluvial aprons and glacial valley walls
Slope--15 to 80 percent
Parent material--colluvium from metasedimentary rock
Mean annual precipitation--about 3000 mm
Mean annual air temperature--about 4 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Loamy-skeletal, isotic Andic Dystrocryepts

TYPICAL PEDON: Mountmystery gravelly silt loam on a southwest facing forested colluvial apron with a slope of 20 percent and an elevation of 1250 m. (The soil was moist throughout when described.)

Oe--0 to 4 cm; moderately decomposed plant material; abrupt wavy boundary

A--4 to 16 cm; brown (10YR 4/3) dry, dark brown (10YR 3/3) gravelly silt loam; moderate medium granular structure; soft, very friable, slightly sticky, moderately plastic; moderately smeary; common very fine and few fine and medium roots; few fine irregular and tubular pores; 15 percent gravel; very strongly acid (pH 4.6); abrupt smooth boundary

Bw1--16 to 30 cm; brown (7.5YR 5/4) dry, brown (7.5YR 4/4) gravelly loam; moderate fine subangular blocky structure; soft, very friable, moderately sticky, moderately plastic; moderately smeary; few very fine, fine, medium, and coarse roots; few fine irregular, tubular, and interstitial pores; 25 percent gravel; very strongly acid (pH 4.7); abrupt smooth boundary

Bw2--30 to 63 cm; yellowish brown (10YR 5/4) dry, brown (10YR 4/3) very gravelly loam; weak very fine subangular blocky structure; soft, very friable, slightly sticky, moderately plastic; weakly smeary; few medium roots; few fine irregular and interstitial pores; 45 percent gravel, 5 percent cobbles; very strongly acid (pH 4.8); clear smooth boundary

Bw3--63 to 150 cm; brown (10YR 5/3) dry, dark grayish brown (10YR 4/2) very gravelly sandy loam; weak very fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; few fine roots; few fine irregular and common fine interstitial pores; 50 percent gravel, 5 percent cobbles; very strongly acid (pH 4.8); clear smooth boundary

TYPE LOCATION: Jefferson County, Washington; near Falls camp on the Gray Wolf pass trail in Olympic National Park
Latitude-- 47.8455050
Longitude-- -123.2680890
Datum--WGS84

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 to 7 degrees C

Particle-size control section
*Clay content--8 to 18 percent
*Total rock fragment content--35 to 60 percent
*Gravel content--30 to 55 percent
*Cobble content--0 to 20 percent
*Stone content--0 to 15 percent

Oe horizon
Thickness--0 to 5 cm

A and Bw1 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 18 percent
Total rock fragment content--10 to 40 percent
Gravel content--5 to 35 percent
Cobble content--0 to 15 percent
Reaction--4.5 to 5.5
Combined thickness--20 to 35 cm

Bw2 and Bw3 horizons
Hue--10YR or 7.5YR
Value--4 or 5 dry or moist
Chroma--2 to 4 dry or moist
Fine-earth texture--silt loam, loam, sandy loam
Clay content--8 to 18 percent
Total rock fragment content--35 to 60 percent
Gravel content--30 to 55 percent
Cobble content--0 to 20 percent
Stone content--0 to 15 percent
Reaction--4.5 to 5.5
Combined thickness--more than 100 cm

COMPETING SERIES:
Angelbasin, Prouty, Smokejump, Tepeh, Twentymile, and Venson--have a mantle of tephra with volcanic glass in the fine earth fraction
Skinwood-- lithic contact within 50 to 100 cm of the soil surface
McCay--paralithic contact within 100 to 150 cm of the soil surface
Hungrycreek--mean annual soil temperature is 0 to 3 degrees C
Hangingglacier and Elklick --lithic contact within 50 to 100 cm of the soil surface

GEOGRAPHIC SETTING:
Elevation--900 to 1300 m
Climate--cool, dry summers; cold, wet winters
Mean annual precipitation--2500 to 3500 mm
Mean annual air temperature--2 to 6 degrees C
Frost-free period--60 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Ignarcreek--albic and spodic horizons; similar landforms
Lakedilly--aquic conditions within 0 to 25 cm of the mineral soil surface; depressions on similar landforms
Allincreek--lithic contact within 25 to 50 cm of the soil surface; 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--mountain hemlock, Pacific silver fir, black huckleberry, Cascade azalea, strawberryleaf raspberry, roughfruit berry

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 Mystery in Olympic National Park

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 29 to 104 cm
*Ochric epipedon
*Andic subgroup features--zone from 4 to 63 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 30 to 150 cm

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National Cooperative Soil Survey
U.S.A.