LOCATION MOUNTSCOTT WA
Tentative Series
IRD. AJF/MGR/MPR
01/2025
MOUNTSCOTT SERIES
Landscape--mountains
Landform--depressions on colluvial aprons and glacial valley walls
Slope--0 to 15 percent
Parent material--colluvium from metasedimentary rock
Mean annual precipitation--about 2500 mm
Mean annual air temperature-- about 9 degrees C
Depth class--very deep
Drainage class--somewhat poorly drained
Soil moisture regime--aquic
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, isotic, acid, frigid Typic Humaquepts
TYPICAL PEDON: Mountscott mucky silt loam on a southeast facing, forested colluvial apron with a slope of 15 percent and an elevation of 1130 m. (The soil was wet throughout when described.)
Oi--0 to 5 cm; slightly decomposed plant material; abrupt wavy boundary
A--5 to 27 cm; very dark gray (10YR 3/1) dry, black (10YR 2/1); mucky silt loam; moderate medium granular structure; soft, very friable, slightly sticky, slightly plastic; moderately smeary; few very fine, fine, medium, and coarse roots; many very fine irregular and tubular pores; very strongly acid (pH 4.6); clear smooth boundary
Bg1--27 to 44 cm; grayish brown (10YR 5/2) dry; dark grayish brown (10YR 4/2); gravelly silt loam; moderate medium subangular blocky structure; soft, very friable, moderately sticky, moderately plastic; weakly smeary; few fine and medium roots; few fine irregular and interstitial pores; 2 percent prominent strong brown (7.5YR 4/6) masses of oxidized iron; 25 percent gravel; very strongly acid (pH 4.7); clear smooth boundary
Bg2--44 to 68 cm; gray (10YR 6/1) dry; gray (10YR 5/1); very gravelly silt loam; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; few very fine roots; few fine irregular and interstitial pores; 40 percent gravel; very strongly acid (pH 4.8); clear smooth boundary
Bg3--68 to 150 cm; gray (10YR 6/1) dry; gray (10YR 5/1); very gravelly silt loam; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common fine interstitial pores; 55 percent gravel; very strongly acid (pH 5.0); clear smooth boundary
TYPE LOCATION: Olympic National Park, Jefferson County, Washington; Graywolf Trail, about 1 mile northeast of Falls Camp.
Latitude--47.861234
Longitude-- -123.271265
Datum--WGS84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5 to 8 degrees C
Mean summer soil temperature--6 to 10 degrees C
Depth to redoximorphic features--25 to 50 below the mineral soil surface
Umbric epipedon thickness--18 to 28 cm
Particle-size control section
*Clay content--8 to 17 percent
*Gravel content--35 to 60 percent
O horizon
Horizon designation--Oi or Oe, or both can be present
Horizon thickness--2 to 10 cm
A horizon
Value--2 or 3 moist or dry
Chroma--1 or 2 moist or dry
Fine-earth texture--silt loam, loam
Clay content--8 to 17 percent
Gravel content--0 to 15 percent
Reaction--4.5 to 5.5
Thickness--18 to 25 cm
Bg1 horizon
Value--4 to 6 moist or dry
Chroma--1 or 2 moist or dry
Fine-earth texture--silt loam, loam
Clay content--8 to 17 percent
Gravel content--25 to 40 percent
Reaction--4.5 to 5.5
Thickness--15 to 25 cm
Bg2 and Bg3 horizons
Value--4 to 6 moist or dry
Chroma--1 or 2 moist or dry
Fine-earth texture--silt loam, loam
Clay content--8 to 17 percent
Gravel content--35 to 60 percent
Reaction--4.5 to 5.5
Combined thickness--90 to 115 cm
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--500 to 1150 m
Climate--warm, dry summers; cool, wet winters
Mean annual precipitation--2000 to 3000 mm
Mean annual air temperature--7 to 11 degrees C
Frost-free period--90 to 150 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Skookumcreek--no aquic conditions; occurs on linear and convex positions of similar landforms
Bonjonpass--has albic and spodic horizons and no aquic conditions; occurs on similar landforms
Charlialakes--moderately deep and no aquic conditions; occurs on ridges and bedrock knobs on similar landforms
Lapoetcreek--coarse loamy textures in particle size control section; occurs on alluvial terraces adjacent to similar landforms
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly
Saturation in normal years--above the surface November through February, seasonally high water table top depth of 25 to 50 cm March to April, 50 to 100 cm May through July, and no saturation August through October.
Flooding--none
Ponding--occasional, brief
Saturated hydraulic conductivity (Ksat)--high or very high throughout
USE AND VEGETATION:
Use--wildlife habitat and recreation
Potential natural vegetation--Pacific silver fir, western hemlock, western redcedar, red alder, salmonberry, devilsclub
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 Mount Scott in Olympic National Park
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 30 to 105 cm
*Umbric epipedon--zone from 5 to 27 cm
*Redoximorphic features--zone from 27 to 150 cm
*Reduced matrix--zone from 44 to 150 cm
National Cooperative Soil Survey
U.S.A.