LOCATION MARMOTPASS              WA

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

MARMOTPASS SERIES

Landscape--mountains
Landform--cirques and structural benches
Slope--0 to 100 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 Humicryepts

TYPICAL PEDON: Marmotpass gravelly silt loam on a southwest facing, non-forested cirque with a slope of 50 percent and an elevation of 1700 m. (The soil was moist throughout when described.)

Oi--0 to 4 cm; slightly decomposed plant material; abrupt wavy boundary

A1--4 to 25 cm; very dark grayish brown (10YR 3/2) dry, black (10YR 2/1) gravelly silt loam; moderate fine granular structure; soft, very friable, slightly sticky, slightly plastic; moderately smeary; many very fine and fine and common medium roots; few fine irregular, interstitial, and tubular pores; 25 percent gravel; very strongly acid (pH 4.6); abrupt smooth boundary

A2--25 to 43 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; weakly smeary; many very fine and fine and common medium roots; few medium interstitial and few fine tubular and irregular pores; 30 percent gravel, 5 percent cobbles; very strongly acid (pH 4.7); clear smooth boundary

Bw1--43 to 60 cm; dark grayish brown (10YR 4/2) dry, very dark grayish brown (10YR 3/2) very gravelly loam; weak fine granular structure; soft, very friable, slightly sticky, slightly plastic; common fine and medium and many very fine roots; common fine interstitial and few fine irregular pores; 40 percent gravel, 5 percent cobbles; very strongly acid (pH 4.8); clear smooth boundary

Bw2--60 to 150 cm; dark grayish brown (10YR 4/2) dry, very dark grayish brown (10YR 3/2) very gravelly loam; weak very fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common very fine and few fine roots; common fine interstitial and few fine irregular pores; 45 percent gravel, 5 percent cobbles; very strongly acid (pH 4.9); clear smooth boundary

TYPE LOCATION: Jefferson County, Washington; near Cedar lake in Olympic National Park
Latitude--47.8337300
Longitude-- -123.2870760
Datum--WGS84

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0 to 7 degrees C
Umbric epipedon thickness--30 to 45 cm

Particle-size control section
*Clay content--8 to 18 percent
*Total rock fragment content--35 to 60 percent
*Gravel content--20 to 50 percent
*Cobble content--0 to 20 percent
*Stone content--0 to 15 percent

Oi horizon
Thickness--0 to 10 cm

A1 and A2 horizons
Value--3 or 4 dry, 2 or 3 moist
Chroma--1 or 2 dry or moist
Fine-earth texture--silt loam, loam, sandy loam
Clay content--8 to 18 percent
Total rock fragment content--20 to 50 percent
Gravel content--20 to 40 percent
Cobble content--0 to 15 percent
Reaction--4.5 to 5.5
Combined thickness--30 to 45 cm

Bw1 and Bw2 horizons
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--35 to 60 percent
Gravel content--20 to 50 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:
Catpeak --lithic contact within 50 to 100 cm of the soil surface
Ahklun, Nagugun-- has a mantle of tephra with volcanic glass in the fine earth fraction
Chiroskey--2C1 and 2C2 horizons have massive structure
Goodlow--Bw horizon particle size control section contains 27 to 35 percent clay and silty clay loam or clay loam textures
Muddycreek--particle size control section contains 3 to 7 percent clay

GEOGRAPHIC SETTING:
Elevation--900 to 1900 m
Climate--cool, dry summers; cold, wet winters
Mean annual precipitation--1500 to 4000 mm
Mean annual air temperature--0 to 6 degrees C
Frost-free period--30 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Lollah--no andic soil properties; similar landforms
Buckinghorsecreek--saturation within 25 to 50 cm during the growing season; drainageways on similar landforms
Ignarcreek--albic and spodic horizons, ochric epipedon; similar landforms
Mountmystery--no umbric epipedon; 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--Rose spirea, common cowparsnip, edible thistle, showy sedge, Alaska brome

DISTRIBUTION AND EXTENT: Olympic Mountains, Washington; MLRA 1; small extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES PROPOSED: Olympic National Park, Jefferson County, Washington 2023; name from Marmot pass in Olympic National Park

REMARKS:
Diagnostic horizons and other features in this pedon:
*Particle-size control section--zone from 29 to 104 cm
*Umbric epipdon--zone from 4 to 43 cm
*Andic subgroup features--zone from 4 to 43 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 43 to 150 cm

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National Cooperative Soil Survey
U.S.A.