LOCATION CRAGCREEK WA
Tentative Series
IRD. AJF/MGR/MPR
01/2025
CRAGCREEK SERIES
Landscape--river valleys
Landform--alluvial terraces
Slope--0 to 15 percent
Parent material--alluvium
Mean annual precipitation--about 2500 mm
Mean annual air temperature-- about 12 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--isomesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Sandy-skeletal, mixed, isomesic Cumulic Humudepts
TYPICAL PEDON: Cragcreek sandy loam on a forested alluvial terrace with a slope of 3 percent and an elevation of 230 m. (The soil was moist throughout when described.)
Oi--0 to 3 cm; slightly decomposed plant material; abrupt smooth boundary
A1--3 to 12 cm; very dark grayish brown (10YR 3/2) dry, black (10YR 2/1); sandy loam; moderate medium granular structure; soft, very friable, non-sticky, slightly plastic; weakly smeary; many very fine and fine, and common medium and very coarse roots; common very fine, fine, and medium irregular and tubular pores; 5 percent gravel, very strongly acid (pH 4.9); abrupt smooth boundary
A2--12 to 20 cm; very dark gray (2.5Y 3/1) dry, black (2.5Y 2.5/1); gravelly loamy sand; weak fine subangular blocky structure; soft, very friable, non-sticky, non-plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine, fine, and medium irregular and tubular pores; 15 percent gravel, very strongly acid (pH 5.1); clear smooth boundary
AB--20 to 54 cm; very dark gray (2.5Y 3/1) dry, black (2.5Y 2.5/1); extremely cobbly loamy sand; weak fine subangular blocky structure; soft, very friable, non-sticky, non-plastic; weakly smeary; many very fine, fine, and medium, and common coarse roots; common medium irregular and tubular pores, and many medium and coarse interstitial pores; 30 percent gravel, 45 percent cobbles; very strongly acid (pH 5.2); gradual smooth boundary
C--54 to 150 cm; very dark gray (2.5Y 3/1) dry, black (2.5Y 2.5/1); extremely cobbly loamy sand; single grain structure; loose, non-sticky, non-plastic; few very fine and fine roots; common fine and medium interstitial pores; 35 percent gravel, 40 percent cobbles, very strongly acid (pH 5.3)
TYPE LOCATION: Olympic National Park, Clallam County, Washington; Hoh River Trail, approximately 100 meters west of Five 5 Mile Camp.
Latitude--47.866096
Longitude-- -123.844635
Datum--WGS84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--10 to 15 degrees C
Mean summer soil temperature--12 to 17 degrees C
Umbric epipedon thickness--50 to 65 cm
Particle-size control section
*Clay content--1 to 7 percent
*Total rock fragment content--60 to 85 percent
*Gravel content--25 to 50 percent
*Cobble content--35 to 50 percent
Oi horizon
Horizon thickness--2 to 10 cm
A horizons
Hue--10YR or 2.5Y
Value--2 to 3 moist or dry
Chroma--1 or 2 moist or dry
Fine-earth texture--sandy loam, loam, loamy sand
Clay content--3 to 10 percent
Gravel content--0 to 15 percent
Reaction--4.5 to 5.5
Combined thickness--18 to 30 cm
AB horizon
Hue--10YR or 2.5Y
Value--2 to 3 moist or dry
Chroma--1 or 2 moist or dry
Fine-earth texture--sandy loam, loamy sand
Clay content--3 to 8 percent
Total rock fragment content--60 to 85 percent
Gravel content--25 to 50 percent
Cobble content--35 to 50 percent
Reaction--4.5 to 5.5
Thickness--25 to 50 cm
C horizon
Hue--10YR or 2.5Y
Value--2 to 4 moist or dry
Chroma--1 or 2 moist or dry
Fine-earth texture--loamy sand, sand
Clay content--1 to 8 percent
Total rock fragment content--60 to 85 percent
Gravel content--25 to 50 percent
Cobble content--35 to 50 percent
Reaction--4.5 to 5.5
Thickness--60 to 105 cm
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--50 to 300 m
Climate--warm, moist summers; mild, wet winters
Mean annual precipitation--2000 to 3000 mm
Mean annual air temperature--10 to 14 degrees C
Frost-free period--180 to 240 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Hatana--has cambic horizon; occurs on similar landforms with less frequent flooding interval
Muscott--somewhat excessively well drained; occurs on similar landforms
Rica--has aquic conditions within 25 to 50 cm of the mineral soil surface; occurs on depressions on similar landforms
Mountmeany--has umbric epipedon and coarse loamy particle size class; occurs on similar landforms with less frequent flooding
Marymere--has loamy-skeletal particle size class and ochric epipedon; occurs on similar landforms with less frequent flooding
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--none
Flooding--rare
Ponding--none
Saturated hydraulic conductivity (Ksat)--high or very high throughout
USE AND VEGETATION:
Use--wildlife habitat and recreation
Potential natural vegetation--Sitka spruce, red alder, black cottonwood, vine maple, salmonberry, western swordfern, Oregon oxalis, dwarf fireweed, common sheep sorrel, trailing blackberry
DISTRIBUTION AND EXTENT: Olympic Mountains and Coast, Washington; MLRA's 1 and 4a; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Olympic National Park, Clallam County, Washington 2023; name from Crag Creek in Olympic National Park
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 28 to 103 cm
*Umbric epipedon--zone from 3 to 54
National Cooperative Soil Survey
U.S.A.